(ping) Add a summary fields CHANGE_SERIAL_NUMBER and CHANGE_ISSUER to DOMAIN_SECURITY_EVENTS

code/common/db/resources/db/migration/V25_01_0_002__ping_domains__cert_serial.sql

@@ -0,0 +1,6 @@
+-- Add additional summary columns to DOMAIN_SECURITY_EVENTS table
+-- to make it easier to make sense of certificate changes
+
+ALTER TABLE DOMAIN_SECURITY_EVENTS ADD COLUMN CHANGE_CERTIFICATE_SERIAL_NUMBER BOOLEAN NOT NULL DEFAULT FALSE;
+ALTER TABLE DOMAIN_SECURITY_EVENTS ADD COLUMN CHANGE_CERTIFICATE_ISSUER BOOLEAN NOT NULL DEFAULT FALSE;
+OPTIMIZE TABLE DOMAIN_SECURITY_EVENTS;

code/execution/java/nu/marginalia/actor/ExecutorActor.java

@@ -12,7 +12,7 @@ public enum ExecutorActor {
     RECRAWL(NodeProfile.BATCH_CRAWL, NodeProfile.MIXED),
     RECRAWL_SINGLE_DOMAIN(NodeProfile.BATCH_CRAWL, NodeProfile.MIXED),
     PROC_CRAWLER_SPAWNER(NodeProfile.BATCH_CRAWL, NodeProfile.MIXED),
-    PROC_PING_SPAWNER(NodeProfile.BATCH_CRAWL, NodeProfile.MIXED, NodeProfile.SIDELOAD),
+    PROC_PING_SPAWNER(NodeProfile.BATCH_CRAWL, NodeProfile.MIXED, NodeProfile.REALTIME),
     PROC_EXPORT_TASKS_SPAWNER(NodeProfile.BATCH_CRAWL, NodeProfile.MIXED),
     ADJACENCY_CALCULATION(NodeProfile.BATCH_CRAWL, NodeProfile.MIXED),
     EXPORT_DATA(NodeProfile.BATCH_CRAWL, NodeProfile.MIXED),

code/execution/java/nu/marginalia/actor/proc/PingMonitorActor.java

@@ -3,24 +3,184 @@ package nu.marginalia.actor.proc;
 import com.google.gson.Gson;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
-import nu.marginalia.actor.monitor.AbstractProcessSpawnerActor;
+import nu.marginalia.actor.prototype.RecordActorPrototype;
+import nu.marginalia.actor.state.ActorResumeBehavior;
+import nu.marginalia.actor.state.ActorStep;
+import nu.marginalia.actor.state.Resume;
+import nu.marginalia.actor.state.Terminal;
+import nu.marginalia.mq.MqMessageState;
+import nu.marginalia.mq.persistence.MqMessageHandlerRegistry;
 import nu.marginalia.mq.persistence.MqPersistence;
 import nu.marginalia.mqapi.ProcessInboxNames;
+import nu.marginalia.mqapi.ping.PingRequest;
+import nu.marginalia.nodecfg.NodeConfigurationService;
+import nu.marginalia.nodecfg.model.NodeProfile;
 import nu.marginalia.process.ProcessService;
 import nu.marginalia.service.module.ServiceConfiguration;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.sql.SQLException;
+import java.util.Set;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 @Singleton
-public class PingMonitorActor extends AbstractProcessSpawnerActor {
+public class PingMonitorActor extends RecordActorPrototype {
 
-    @Inject
-    public PingMonitorActor(Gson gson, ServiceConfiguration configuration, MqPersistence persistence, ProcessService processService) {
-        super(gson,
-                configuration,
-                persistence,
-                processService,
-                ProcessInboxNames.PING_INBOX,
-                ProcessService.ProcessId.PING);
+    private final MqPersistence persistence;
+    private final ProcessService processService;
+
+    private final Logger logger = LoggerFactory.getLogger(getClass());
+
+    public static final int MAX_ATTEMPTS = 3;
+    private final String inboxName;
+    private final ProcessService.ProcessId processId;
+    private final ExecutorService executorService = Executors.newSingleThreadExecutor();
+    private final int node;
+    private final boolean isPrimaryNode;
+    private final Gson gson;
+
+    public record Initial() implements ActorStep {}
+    @Resume(behavior = ActorResumeBehavior.RETRY)
+    public record Monitor(int errorAttempts) implements ActorStep {}
+    @Resume(behavior = ActorResumeBehavior.RESTART)
+    public record Run(int attempts) implements ActorStep {}
+    @Terminal
+    public record Aborted() implements ActorStep {}
+
+    @Override
+    public ActorStep transition(ActorStep self) throws Exception {
+        return switch (self) {
+            case Initial i -> {
+                PingRequest request = new PingRequest(isPrimaryNode ? "primary": "secondary");
+
+                persistence.sendNewMessage(inboxName, null, null,
+                        "PingRequest",
+                        gson.toJson(request),
+                        null);
+
+                yield new Monitor(0);
+            }
+            case Monitor(int errorAttempts) -> {
+                for (;;) {
+                    var messages = persistence.eavesdrop(inboxName, 1);
+
+                    if (messages.isEmpty() && !processService.isRunning(processId)) {
+                        synchronized (processId) {
+                            processId.wait(5000);
+                        }
+
+                        if (errorAttempts > 0) { // Reset the error counter if there is silence in the inbox
+                            yield new Monitor(0);
+                        }
+                        // else continue
+                    } else {
+                        // Special: Associate this thread with the message so that we can get tracking
+                        MqMessageHandlerRegistry.register(messages.getFirst().msgId());
+
+                        yield new Run(0);
+                    }
+                }
+            }
+            case Run(int attempts) -> {
+                try {
+                    long startTime = System.currentTimeMillis();
+                    var exec = new TaskExecution();
+                    long endTime = System.currentTimeMillis();
+
+                    if (exec.isError()) {
+                        if (attempts < MAX_ATTEMPTS)
+                            yield new Run(attempts + 1);
+                        else
+                            yield new Error();
+                    }
+                    else if (endTime - startTime < TimeUnit.SECONDS.toMillis(1)) {
+                        // To avoid boot loops, we transition to error if the process
+                        // didn't run for longer than 1 seconds.  This might happen if
+                        // the process crashes before it can reach the heartbeat and inbox
+                        // stages of execution.  In this case it would not report having acted
+                        // on its message, and the process would be restarted forever without
+                        // the attempts counter incrementing.
+                        yield new Error("Process terminated within 1 seconds of starting");
+                    }
+                }
+                catch (InterruptedException ex) {
+                    // We get this exception when the process is cancelled by the user
+
+                    processService.kill(processId);
+                    setCurrentMessageToDead();
+
+                    yield new Aborted();
+                }
+
+                yield new Monitor(attempts);
+            }
+            default -> new Error();
+        };
     }
 
+    public String describe() {
+        return "Spawns a(n) " + processId +  " process and monitors its inbox for messages";
+    }
 
+    @Inject
+    public PingMonitorActor(Gson gson,
+                                       NodeConfigurationService nodeConfigurationService,
+                                       ServiceConfiguration configuration,
+                                       MqPersistence persistence,
+                                       ProcessService processService) throws SQLException {
+        super(gson);
+        this.gson = gson;
+        this.node = configuration.node();
+        this.persistence = persistence;
+        this.processService = processService;
+        this.inboxName = ProcessInboxNames.PING_INBOX + ":" + node;
+        this.processId = ProcessService.ProcessId.PING;
+
+        this.isPrimaryNode = Set.of(NodeProfile.BATCH_CRAWL, NodeProfile.MIXED)
+                .contains(nodeConfigurationService.get(node).profile());
+    }
+
+    /** Sets the message to dead in the database to avoid
+     * the service respawning on the same task when we
+     * re-enable this actor */
+    private void setCurrentMessageToDead() {
+        try {
+            var messages = persistence.eavesdrop(inboxName, 1);
+
+            if (messages.isEmpty()) // Possibly a race condition where the task is already finished
+                return;
+
+            var theMessage = messages.iterator().next();
+            persistence.updateMessageState(theMessage.msgId(), MqMessageState.DEAD);
+        }
+        catch (SQLException ex) {
+            logger.error("Tried but failed to set the message for " + processId + " to dead", ex);
+        }
+    }
+
+    /** Encapsulates the execution of the process in a separate thread so that
+     * we can interrupt the thread if the process is cancelled */
+    private class TaskExecution {
+        private final AtomicBoolean error = new AtomicBoolean(false);
+        public TaskExecution() throws ExecutionException, InterruptedException {
+            // Run this call in a separate thread so that this thread can be interrupted waiting for it
+            executorService.submit(() -> {
+                try {
+                    processService.trigger(processId);
+                } catch (Exception e) {
+                    logger.warn("Error in triggering process", e);
+                    error.set(true);
+                }
+            }).get(); // Wait for the process to start
+        }
+
+        public boolean isError() {
+            return error.get();
+        }
+    }
 }

code/features-search/random-websites/java/nu/marginalia/browse/DbBrowseDomainsRandom.java

@@ -27,10 +27,12 @@ public class DbBrowseDomainsRandom {
     public List<BrowseResult> getRandomDomains(int count, DomainBlacklist blacklist, int set) {
 
         final String q = """
-                SELECT DOMAIN_ID, DOMAIN_NAME, INDEXED
+                SELECT EC_RANDOM_DOMAINS.DOMAIN_ID, DOMAIN_NAME, INDEXED
                 FROM EC_RANDOM_DOMAINS
                 INNER JOIN EC_DOMAIN ON EC_DOMAIN.ID=DOMAIN_ID
+                LEFT JOIN DOMAIN_AVAILABILITY_INFORMATION DAI ON DAI.DOMAIN_ID=EC_RANDOM_DOMAINS.DOMAIN_ID
                 WHERE STATE<2
+                AND SERVER_AVAILABLE
                 AND DOMAIN_SET=?
                 AND DOMAIN_ALIAS IS NULL
                 ORDER BY RAND()

code/processes/ping-process/java/nu/marginalia/ping/PingDao.java

@@ -15,6 +15,7 @@ import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Objects;
 
 @Singleton
 public class PingDao {
@@ -76,32 +77,6 @@ public class PingDao {
         }
     }
 
-    public List<DomainReference> getNewDomains(int nodeId, int cnt) throws SQLException {
-        List<DomainReference> domains = new ArrayList<>();
-        try (var conn = dataSource.getConnection();
-             var ps = conn.prepareStatement("""
-            SELECT domain_id, domain_name
-            FROM EC_DOMAIN 
-            LEFT JOIN DOMAIN_AVAILABILITY_INFORMATION 
-            ON EC_DOMAIN.domain_id = DOMAIN_AVAILABILITY_INFORMATION.domain_id
-            WHERE DOMAIN_AVAILABILITY_INFORMATION.server_available IS NULL
-            AND EC_DOMAIN.NODE_ID = ?
-            LIMIT ?
-            """))
-        {
-            ps.setInt(1, nodeId);
-            ps.setInt(2, cnt);
-
-            ResultSet rs = ps.executeQuery();
-
-            while (rs.next()) {
-                domains.add(new DomainReference(rs.getInt("domain_id"), nodeId, rs.getString("domain_name").toLowerCase()));
-            }
-        }
-
-        return domains;
-    }
-
     public DomainAvailabilityRecord getDomainPingStatus(int domainId) throws SQLException {
 
         try (var conn = dataSource.getConnection();
@@ -132,7 +107,7 @@ public class PingDao {
         }
     }
 
-    public DomainDnsRecord getDomainDnsRecord(int dnsRootDomainId) throws SQLException {
+    public DomainDnsRecord getDomainDnsRecord(long dnsRootDomainId) throws SQLException {
         try (var conn = dataSource.getConnection();
              var ps = conn.prepareStatement("SELECT * FROM DOMAIN_DNS_INFORMATION WHERE DNS_ROOT_DOMAIN_ID = ?")) {
 
@@ -160,111 +135,123 @@ public class PingDao {
         }
     }
 
-    public List<HistoricalAvailabilityData> getNextDomainPingStatuses(int count, int nodeId) throws SQLException {
-        List<HistoricalAvailabilityData> domainAvailabilityRecords = new ArrayList<>(count);
-
+    public HistoricalAvailabilityData getHistoricalAvailabilityData(long domainId) throws SQLException {
         var query = """
-            SELECT DOMAIN_AVAILABILITY_INFORMATION.*, DOMAIN_SECURITY_INFORMATION.*, EC_DOMAIN.DOMAIN_NAME FROM DOMAIN_AVAILABILITY_INFORMATION
-                LEFT JOIN DOMAIN_SECURITY_INFORMATION
-                ON DOMAIN_AVAILABILITY_INFORMATION.DOMAIN_ID = DOMAIN_SECURITY_INFORMATION.DOMAIN_ID
-                INNER JOIN EC_DOMAIN ON EC_DOMAIN.ID = DOMAIN_AVAILABILITY_INFORMATION.DOMAIN_ID
-            WHERE NEXT_SCHEDULED_UPDATE <= ? AND DOMAIN_AVAILABILITY_INFORMATION.NODE_ID = ?
-            ORDER BY NEXT_SCHEDULED_UPDATE ASC
-            LIMIT ?
+            SELECT EC_DOMAIN.ID, EC_DOMAIN.DOMAIN_NAME, EC_DOMAIN.NODE_AFFINITY, DOMAIN_AVAILABILITY_INFORMATION.*, DOMAIN_SECURITY_INFORMATION.*
+                FROM EC_DOMAIN
+                LEFT JOIN DOMAIN_SECURITY_INFORMATION ON DOMAIN_SECURITY_INFORMATION.DOMAIN_ID = EC_DOMAIN.ID
+                LEFT JOIN DOMAIN_AVAILABILITY_INFORMATION ON DOMAIN_AVAILABILITY_INFORMATION.DOMAIN_ID = EC_DOMAIN.ID
+                WHERE EC_DOMAIN.ID = ?
             """;
         try (var conn = dataSource.getConnection();
              var ps = conn.prepareStatement(query)) {
-            // Use Java time since this is how we generate the timestamps in the ping process
-            // to avoid timezone weirdness.
-            ps.setTimestamp(1, java.sql.Timestamp.from(Instant.now()));
-            ps.setInt(2, nodeId);
-            ps.setInt(3, count);
+
+            ps.setLong(1, domainId);
+
             ResultSet rs = ps.executeQuery();
             while (rs.next()) {
                 String domainName = rs.getString("EC_DOMAIN.DOMAIN_NAME");
-                var domainAvailabilityRecord = new DomainAvailabilityRecord(rs);
-                if (rs.getObject("DOMAIN_SECURITY_INFORMATION.DOMAIN_ID", Integer.class) != null) {
-                    var securityRecord = new DomainSecurityRecord(rs);
-                    domainAvailabilityRecords.add(
-                        new HistoricalAvailabilityData.AvailabilityAndSecurity(domainName, domainAvailabilityRecord, securityRecord)
-                    );
-                } else {
-                    domainAvailabilityRecords.add(new HistoricalAvailabilityData.JustAvailability(domainName, domainAvailabilityRecord));
+
+                DomainAvailabilityRecord dar;
+                DomainSecurityRecord dsr;
+
+                if (rs.getObject("DOMAIN_SECURITY_INFORMATION.DOMAIN_ID", Integer.class) != null)
+                    dsr = new DomainSecurityRecord(rs);
+                else
+                    dsr = null;
+
+                if (rs.getObject("DOMAIN_AVAILABILITY_INFORMATION.DOMAIN_ID", Integer.class) != null)
+                    dar = new DomainAvailabilityRecord(rs);
+                else
+                    dar = null;
+
+                if (dar == null) {
+                    return new HistoricalAvailabilityData.JustDomainReference(new DomainReference(
+                            rs.getInt("EC_DOMAIN.ID"),
+                            rs.getInt("EC_DOMAIN.NODE_AFFINITY"),
+                            domainName.toLowerCase()
+                    ));
+                }
+                else {
+                    if (dsr != null) {
+                        return new HistoricalAvailabilityData.AvailabilityAndSecurity(domainName, dar, dsr);
+                    } else {
+                        return new HistoricalAvailabilityData.JustAvailability(domainName, dar);
+                    }
                 }
             }
         }
-        return domainAvailabilityRecords;
+
+        return null;
     }
 
-    public List<DomainDnsRecord> getNextDnsDomainRecords(int count, int nodeId) throws SQLException {
-        List<DomainDnsRecord> domainDnsRecords = new ArrayList<>(count);
+    public List<UpdateSchedule.UpdateJob<Long, HistoricalAvailabilityData>> getDomainUpdateSchedule(int nodeId) {
+        List<UpdateSchedule.UpdateJob<Long, HistoricalAvailabilityData>> updateJobs = new ArrayList<>();
 
-        var query = """
-            SELECT * FROM DOMAIN_DNS_INFORMATION
-            WHERE TS_NEXT_DNS_CHECK <= ? AND NODE_AFFINITY = ?
-            ORDER BY DNS_CHECK_PRIORITY DESC, TS_NEXT_DNS_CHECK ASC
-            LIMIT ?
-            """;
         try (var conn = dataSource.getConnection();
-             var ps = conn.prepareStatement(query)) {
-            ps.setTimestamp(1, java.sql.Timestamp.from(Instant.now()));
-            ps.setInt(2, nodeId);
-            ps.setInt(3, count);
+             var ps = conn.prepareStatement("""
+                SELECT ID, NEXT_SCHEDULED_UPDATE
+                FROM EC_DOMAIN
+                LEFT JOIN DOMAIN_AVAILABILITY_INFORMATION
+                ON EC_DOMAIN.ID = DOMAIN_AVAILABILITY_INFORMATION.DOMAIN_ID
+                WHERE NODE_AFFINITY = ?
+                """)) {
+            ps.setFetchSize(10_000);
+            ps.setInt(1, nodeId);
             ResultSet rs = ps.executeQuery();
             while (rs.next()) {
-                domainDnsRecords.add(new DomainDnsRecord(rs));
+                long domainId = rs.getLong("ID");
+                var ts = rs.getTimestamp("NEXT_SCHEDULED_UPDATE");
+                Instant nextUpdate = ts == null ? Instant.now() : ts.toInstant();
+
+                updateJobs.add(new UpdateSchedule.UpdateJob<>(domainId, nextUpdate));
             }
+        } catch (SQLException e) {
+            throw new RuntimeException("Failed to retrieve domain update schedule", e);
         }
-        return domainDnsRecords;
+
+        logger.info("Found {} availability update jobs for node {}", updateJobs.size(), nodeId);
+
+        return updateJobs;
     }
 
-    public List<DomainReference> getOrphanedDomains(int nodeId) {
-        List<DomainReference> orphanedDomains = new ArrayList<>();
+    public List<UpdateSchedule.UpdateJob<RootDomainReference, RootDomainReference>> getDnsUpdateSchedule(int nodeId) {
+        List<UpdateSchedule.UpdateJob<RootDomainReference, RootDomainReference>> updateJobs = new ArrayList<>();
+
         try (var conn = dataSource.getConnection();
-            var stmt = conn.prepareStatement("""
-                SELECT e.DOMAIN_NAME, e.ID
-                FROM EC_DOMAIN e
-                LEFT JOIN DOMAIN_AVAILABILITY_INFORMATION d ON e.ID = d.DOMAIN_ID
-                WHERE d.DOMAIN_ID IS NULL AND e.NODE_AFFINITY = ?;
+             var ps = conn.prepareStatement("""
+                SELECT DISTINCT(DOMAIN_TOP),DOMAIN_DNS_INFORMATION.* FROM EC_DOMAIN
+                LEFT JOIN DOMAIN_DNS_INFORMATION ON ROOT_DOMAIN_NAME = DOMAIN_TOP
+                WHERE EC_DOMAIN.NODE_AFFINITY = ?
                 """)) {
-            stmt.setInt(1, nodeId);
-            stmt.setFetchSize(10_000);
-            ResultSet rs = stmt.executeQuery();
+            ps.setFetchSize(10_000);
+            ps.setInt(1, nodeId);
+            ResultSet rs = ps.executeQuery();
             while (rs.next()) {
-                String domainName = rs.getString("DOMAIN_NAME");
-                int domainId = rs.getInt("ID");
+                Long dnsRootDomainId = rs.getObject("DOMAIN_DNS_INFORMATION.DNS_ROOT_DOMAIN_ID", Long.class);
+                String rootDomainName = rs.getString("DOMAIN_TOP");
 
-                orphanedDomains.add(new DomainReference(domainId, nodeId, domainName));
+                if (dnsRootDomainId == null) {
+                    updateJobs.add(
+                            new UpdateSchedule.UpdateJob<>(
+                            new RootDomainReference.ByName(rootDomainName),
+                            Instant.now())
+                    );
+                }
+                else {
+                    var record = new DomainDnsRecord(rs);
+                    updateJobs.add(new UpdateSchedule.UpdateJob<>(
+                            new RootDomainReference.ById(dnsRootDomainId),
+                            Objects.requireNonNullElseGet(record.tsNextScheduledUpdate(), Instant::now))
+                    );
+                }
             }
-        }
-        catch (SQLException e) {
-            throw new RuntimeException("Failed to retrieve orphaned domains", e);
+        } catch (SQLException e) {
+            throw new RuntimeException("Failed to retrieve DNS update schedule", e);
         }
 
-        return orphanedDomains;
-    }
+        logger.info("Found {} dns update jobs for node {}", updateJobs.size(), nodeId);
 
-    public List<String> getOrphanedRootDomains(int nodeId) {
-        List<String> orphanedDomains = new ArrayList<>();
-        try (var conn = dataSource.getConnection();
-             var stmt = conn.prepareStatement("""
-                SELECT DISTINCT(DOMAIN_TOP)
-                FROM EC_DOMAIN e
-                LEFT JOIN DOMAIN_DNS_INFORMATION d ON e.DOMAIN_TOP = d.ROOT_DOMAIN_NAME
-                WHERE d.ROOT_DOMAIN_NAME IS NULL AND e.NODE_AFFINITY = ?;
-                """)) {
-            stmt.setInt(1, nodeId);
-            stmt.setFetchSize(10_000);
-            ResultSet rs = stmt.executeQuery();
-            while (rs.next()) {
-                String domainName = rs.getString("DOMAIN_TOP");
-                orphanedDomains.add(domainName.toLowerCase());
-            }
-        }
-        catch (SQLException e) {
-            throw new RuntimeException("Failed to retrieve orphaned domains", e);
-        }
-
-        return orphanedDomains;
+        return updateJobs;
     }
 }

code/processes/ping-process/java/nu/marginalia/ping/PingJobScheduler.java

@@ -4,15 +4,15 @@ import com.google.inject.Inject;
 import nu.marginalia.ping.model.*;
 import nu.marginalia.ping.svc.DnsPingService;
 import nu.marginalia.ping.svc.HttpPingService;
-import org.jetbrains.annotations.NotNull;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import javax.annotation.Nullable;
+import java.time.Duration;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.ArrayBlockingQueue;
-import java.util.concurrent.ConcurrentHashMap;
+import java.util.Objects;
 import java.util.concurrent.TimeUnit;
 
 /** PingJobScheduler is responsible for scheduling and processing ping jobs
@@ -27,50 +27,13 @@ public class PingJobScheduler {
 
     private static final Logger logger = LoggerFactory.getLogger(PingJobScheduler.class);
 
-    sealed interface DnsJob {
-        Object reference();
+    private static final UpdateSchedule<RootDomainReference, RootDomainReference> dnsUpdateSchedule
+            = new UpdateSchedule<>(250_000);
+    private static final UpdateSchedule<Long, HistoricalAvailabilityData> availabilityUpdateSchedule
+            = new UpdateSchedule<>(250_000);
 
-        record DnsFetch(String rootDomain) implements DnsJob {
-            @Override
-            public Object reference() {
-                return rootDomain;
-            }
-        }
-        record DnsRefresh(DomainDnsRecord oldRecord) implements DnsJob {
-            @Override
-            public Object reference() {
-                return oldRecord.rootDomainName();
-            }
-        }
-    }
-
-    sealed interface AvailabilityJob {
-        Object reference();
-
-        record Availability(DomainReference domainReference) implements AvailabilityJob {
-            @Override
-            public Object reference() {
-                return domainReference.domainName();
-            }
-        }
-        record AvailabilityRefresh(String domain, @NotNull DomainAvailabilityRecord availability, @Nullable DomainSecurityRecord securityRecord) implements AvailabilityJob {
-            @Override
-            public Object reference() {
-                return domain;
-            }
-        }
-    }
-
-    // Keeps track of ongoing ping and DNS processing to avoid duplicate work,
-    // which is mainly a scenario that will occur when there is not a lot of data
-    // in the database.  In real-world scenarios, the queues will be full most
-    // of the time, and prevent this from being an issue.
-
-    private static final ConcurrentHashMap<Object, Boolean> processingDomainsAvailability = new ConcurrentHashMap<>();
-    private static final ConcurrentHashMap<Object, Boolean> processingDomainsDns = new ConcurrentHashMap<>();
-
-    private static final ArrayBlockingQueue<DnsJob> dnsJobQueue = new ArrayBlockingQueue<>(8);
-    private static final ArrayBlockingQueue<AvailabilityJob> availabilityJobQueue = new ArrayBlockingQueue<>(8);
+    public volatile Instant dnsLastSync = Instant.now();
+    public volatile Instant availabilityLastSync = Instant.now();
 
     public volatile Integer nodeId = null;
     public volatile boolean running = false;
@@ -95,15 +58,16 @@ public class PingJobScheduler {
 
         running = true;
 
-        allThreads.add(Thread.ofPlatform().daemon().name("new-dns").start(this::fetchNewDnsRecords));
-        allThreads.add(Thread.ofPlatform().daemon().name("new-availability").start(this::fetchNewAvailabilityJobs));
-        allThreads.add(Thread.ofPlatform().daemon().name("update-availability").start(this::updateAvailabilityJobs));
-        allThreads.add(Thread.ofPlatform().daemon().name("update-dns").start(this::updateDnsJobs));
+        allThreads.add(Thread.ofPlatform().daemon().name("sync-dns").start(this::syncAvailabilityJobs));
+        allThreads.add(Thread.ofPlatform().daemon().name("sync-availability").start(this::syncDnsRecords));
 
-        for (int i = 0; i < 8; i++) {
+        int availabilityThreads = Integer.getInteger("ping.availabilityThreads", 8);
+        int pingThreads = Integer.getInteger("ping.dnsThreads", 2);
+
+        for (int i = 0; i < availabilityThreads; i++) {
             allThreads.add(Thread.ofPlatform().daemon().name("availability-job-consumer-" + i).start(this::availabilityJobConsumer));
         }
-        for (int i = 0; i < 1; i++) {
+        for (int i = 0; i < pingThreads; i++) {
             allThreads.add(Thread.ofPlatform().daemon().name("dns-job-consumer-" + i).start(this::dnsJobConsumer));
         }
     }
@@ -122,19 +86,33 @@ public class PingJobScheduler {
     }
 
     public void pause(int nodeId) {
+        logger.info("Pausing PingJobScheduler for nodeId: {}", nodeId);
+
         if (this.nodeId != null && this.nodeId != nodeId) {
             logger.warn("Attempted to pause PingJobScheduler with mismatched nodeId: expected {}, got {}", this.nodeId, nodeId);
             return;
         }
         this.nodeId = null;
+
+        availabilityUpdateSchedule.clear();
+        dnsUpdateSchedule.clear();
+
         logger.info("PingJobScheduler paused");
     }
 
     public synchronized void resume(int nodeId) {
+        logger.info("Resuming PingJobScheduler for nodeId: {}", nodeId);
         if (this.nodeId != null) {
-            logger.warn("Attempted to resume PingJobScheduler with mismatched nodeId: expected null, got {}", this.nodeId, nodeId);
+            logger.warn("Attempted to resume PingJobScheduler with mismatched nodeId: expected {}, got {}", this.nodeId, nodeId);
             return;
         }
+
+        availabilityUpdateSchedule.replaceQueue(pingDao.getDomainUpdateSchedule(nodeId));
+        dnsUpdateSchedule.replaceQueue(pingDao.getDnsUpdateSchedule(nodeId));
+        dnsLastSync = Instant.now();
+        availabilityLastSync = Instant.now();
+
+        // Flag that we are running again
         this.nodeId = nodeId;
 
         notifyAll();
@@ -150,32 +128,44 @@ public class PingJobScheduler {
     private void availabilityJobConsumer() {
         while (running) {
             try {
-                AvailabilityJob job = availabilityJobQueue.poll(1, TimeUnit.SECONDS);
-                if (job == null) {
-                    continue; // No job available, continue to the next iteration
+                Integer nid = nodeId;
+                if (nid == null) {
+                    waitForResume();
+                    continue;
+                }
+
+                long nextId = availabilityUpdateSchedule.next();
+                var data = pingDao.getHistoricalAvailabilityData(nextId);
+                if (data == null) {
+                    logger.warn("No availability data found for ID: {}", nextId);
+                    continue; // No data to process, skip this iteration
                 }
 
                 try {
-                    switch (job) {
-                        case AvailabilityJob.Availability(DomainReference reference) -> {
-                            logger.info("Availability check: {}", reference.domainName());
-                            pingDao.write(httpPingService.pingDomain(reference, null, null));
-                        }
-                        case AvailabilityJob.AvailabilityRefresh(String domain, DomainAvailabilityRecord availability, DomainSecurityRecord security) -> {
-                            logger.info("Availability check with reference: {}", domain);
-                            pingDao.write(httpPingService.pingDomain(
-                                    new DomainReference(availability.domainId(), availability.nodeId(), domain),
-                                    availability,
-                                    security));
+                    List<WritableModel> objects = switch (data) {
+                        case HistoricalAvailabilityData.JustDomainReference(DomainReference reference)
+                                -> httpPingService.pingDomain(reference, null, null);
+                        case HistoricalAvailabilityData.JustAvailability(String domain, DomainAvailabilityRecord record)
+                                -> httpPingService.pingDomain(
+                                    new DomainReference(record.domainId(), record.nodeId(), domain), record, null);
+                        case HistoricalAvailabilityData.AvailabilityAndSecurity(String domain, DomainAvailabilityRecord availability, DomainSecurityRecord security)
+                                -> httpPingService.pingDomain(
+                                        new DomainReference(availability.domainId(), availability.nodeId(), domain), availability, security);
+                    };
+
+                    pingDao.write(objects);
+
+                    // Re-schedule the next update time for the domain
+                    for (var object : objects) {
+                        var ts = object.nextUpdateTime();
+                        if (ts != null) {
+                            availabilityUpdateSchedule.add(nextId, ts);
+                            break;
                         }
                     }
                 }
                 catch (Exception e) {
-                    logger.error("Error processing availability job for domain: " + job.reference(), e);
-                }
-                finally {
-                    // Remove the domain from the processing map
-                    processingDomainsAvailability.remove(job.reference());
+                    logger.error("Error processing availability job for domain: " + data.domain(), e);
                 }
             } catch (InterruptedException e) {
                 Thread.currentThread().interrupt();
@@ -190,30 +180,41 @@ public class PingJobScheduler {
     private void dnsJobConsumer() {
         while (running) {
             try {
-                DnsJob job = dnsJobQueue.poll(1, TimeUnit.SECONDS);
-                if (job == null) {
-                    continue; // No job available, continue to the next iteration
+                Integer nid = nodeId;
+                if (nid == null) {
+                    waitForResume();
+                    continue;
                 }
 
+                RootDomainReference ref = dnsUpdateSchedule.next();
+
                 try {
-                    switch (job) {
-                        case DnsJob.DnsFetch(String rootDomain) -> {
-                            logger.info("Fetching DNS records for root domain: {}", rootDomain);
-                            pingDao.write(dnsPingService.pingDomain(rootDomain, null));
+                    List<WritableModel> objects = switch(ref) {
+                        case RootDomainReference.ById(long id) -> {
+                            var oldRecord = Objects.requireNonNull(pingDao.getDomainDnsRecord(id));
+                            yield dnsPingService.pingDomain(oldRecord.rootDomainName(), oldRecord);
                         }
-                        case DnsJob.DnsRefresh(DomainDnsRecord oldRecord) -> {
-                            logger.info("Refreshing DNS records for domain: {}", oldRecord.rootDomainName());
-                            pingDao.write(dnsPingService.pingDomain(oldRecord.rootDomainName(), oldRecord));
+                        case RootDomainReference.ByName(String name) -> {
+                            @Nullable var oldRecord = pingDao.getDomainDnsRecord(name);
+                            yield dnsPingService.pingDomain(name, oldRecord);
+                        }
+                    };
+
+                    pingDao.write(objects);
+
+                    // Re-schedule the next update time for the domain
+                    for (var object : objects) {
+                        var ts = object.nextUpdateTime();
+                        if (ts != null) {
+                            dnsUpdateSchedule.add(ref, ts);
+                            break;
                         }
                     }
                 }
                 catch (Exception e) {
-                    logger.error("Error processing DNS job for domain: " + job.reference(), e);
-                }
-                finally {
-                    // Remove the domain from the processing map
-                    processingDomainsDns.remove(job.reference());
+                    logger.error("Error processing DNS job for domain: " + ref, e);
                 }
+
             } catch (InterruptedException e) {
                 Thread.currentThread().interrupt();
                 logger.error("DNS job consumer interrupted", e);
@@ -224,38 +225,27 @@ public class PingJobScheduler {
         }
     }
 
-    private void fetchNewAvailabilityJobs() {
+    private void syncAvailabilityJobs() {
         try {
             while (running) {
 
+                // If we are suspended, wait for resume
                 Integer nid = nodeId;
                 if (nid == null) {
                     waitForResume();
-                    continue; // re-fetch the records after resuming
+                    continue;
                 }
 
-                List<DomainReference> domains = pingDao.getOrphanedDomains(nid);
-                for (DomainReference domain : domains) {
-
-                    if (nodeId == null) {
-                        waitForResume();
-                        break; // re-fetch the records after resuming
-                    }
-
-                    try {
-                        availabilityJobQueue.put(new AvailabilityJob.Availability(domain));
-                    } catch (InterruptedException e) {
-                        Thread.currentThread().interrupt();
-                        logger.error("Failed to add new ping job for domain: " + domain, e);
-                    }
+                // Check if we need to refresh the availability data
+                Instant nextRefresh = availabilityLastSync.plus(Duration.ofHours(24));
+                if (Instant.now().isBefore(nextRefresh)) {
+                    Duration remaining = Duration.between(Instant.now(), nextRefresh);
+                    TimeUnit.MINUTES.sleep(Math.max(1, remaining.toMinutes()));
+                    continue;
                 }
 
-                // This is an incredibly expensive operation, so we only do it once a day
-                try {
-                    TimeUnit.HOURS.sleep(24);
-                } catch (InterruptedException e) {
-                    throw new RuntimeException(e);
-                }
+                availabilityUpdateSchedule.replaceQueue(pingDao.getDomainUpdateSchedule(nid));
+                availabilityLastSync = Instant.now();
             }
         }
         catch (Exception e) {
@@ -263,32 +253,26 @@ public class PingJobScheduler {
         }
     }
 
-    private void fetchNewDnsRecords() {
+    private void syncDnsRecords() {
         try {
             while (running) {
+
                 Integer nid = nodeId;
                 if (nid == null) {
                     waitForResume();
                     continue; // re-fetch the records after resuming
                 }
 
-                List<String> rootDomains = pingDao.getOrphanedRootDomains(nid);
-                for (String rootDomain : rootDomains) {
-
-                    if (nodeId == null) {
-                        waitForResume();
-                        break; // re-fetch the records after resuming
-                    }
-
-                    try {
-                        dnsJobQueue.put(new DnsJob.DnsFetch(rootDomain));
-                    } catch (InterruptedException e) {
-                        Thread.currentThread().interrupt();
-                        logger.error("Failed to add new DNS job for root domain: " + rootDomain, e);
-                    }
+                // Check if we need to refresh the availability data
+                Instant nextRefresh = dnsLastSync.plus(Duration.ofHours(24));
+                if (Instant.now().isBefore(nextRefresh)) {
+                    Duration remaining = Duration.between(Instant.now(), nextRefresh);
+                    TimeUnit.MINUTES.sleep(Math.max(1, remaining.toMinutes()));
+                    continue;
                 }
-                // This is an incredibly expensive operation, so we only do it once a day
-                TimeUnit.HOURS.sleep(24);
+
+                dnsUpdateSchedule.replaceQueue(pingDao.getDnsUpdateSchedule(nid));
+                dnsLastSync = Instant.now();
             }
         } catch (InterruptedException e) {
             Thread.currentThread().interrupt();
@@ -296,68 +280,5 @@ public class PingJobScheduler {
         }
     }
 
-    private void updateAvailabilityJobs() {
-
-        while (running) {
-            try {
-                Integer nid = nodeId;
-                if (nid == null) {
-                    waitForResume();
-                    continue; // re-fetch the records after resuming
-                }
-
-                var statuses = pingDao.getNextDomainPingStatuses(100, nid);
-
-                if (nodeId == null) {
-                    waitForResume();
-                    break; // re-fetch the records after resuming
-                }
-
-                for (var status : statuses) {
-                    var job = switch (status) {
-                        case HistoricalAvailabilityData.JustAvailability(String domain, DomainAvailabilityRecord record)
-                                -> new AvailabilityJob.AvailabilityRefresh(domain, record, null);
-                        case HistoricalAvailabilityData.AvailabilityAndSecurity(String domain, DomainAvailabilityRecord availability, DomainSecurityRecord security)
-                                -> new AvailabilityJob.AvailabilityRefresh(domain, availability, security);
-                    };
-
-                    if (processingDomainsAvailability.putIfAbsent(job.reference(), true) == null) {
-                        availabilityJobQueue.put(job);
-                    }
-
-                }
-            }
-            catch (Exception e) {
-                logger.error("Error fetching next domain ping statuses", e);
-            }
-        }
-
-    }
-
-    private void updateDnsJobs() {
-        while (running) {
-            try {
-                Integer nid = nodeId;
-                if (nid == null) {
-                    waitForResume();
-                    continue; // re-fetch the records after resuming
-                }
-
-                var dnsRecords = pingDao.getNextDnsDomainRecords(1000, nid);
-                for (var record : dnsRecords) {
-                    if (nodeId == null) {
-                        waitForResume();
-                        break; // re-fetch the records after resuming
-                    }
-                    if (processingDomainsDns.putIfAbsent(record.rootDomainName(), true) == null) {
-                        dnsJobQueue.put(new DnsJob.DnsRefresh(record));
-                    }
-                }
-            }
-            catch (Exception e) {
-                logger.error("Error fetching next domain DNS records", e);
-            }
-        }
-    }
 
 }

code/processes/ping-process/java/nu/marginalia/ping/UpdateSchedule.java

@@ -0,0 +1,57 @@
+package nu.marginalia.ping;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.PriorityQueue;
+
+/** In-memory schedule for updates, allowing jobs to be added and processed in order of their scheduled time.
+ * This is not a particularly high-performance implementation, but exists to take contention off the database's
+ * timestamp index.
+ * */
+public class UpdateSchedule<T, T2> {
+    private final PriorityQueue<UpdateJob<T, T2>> updateQueue;
+    public record UpdateJob<T, T2>(T key, Instant updateTime) {}
+
+    public UpdateSchedule(int initialCapacity) {
+        updateQueue = new PriorityQueue<>(initialCapacity, Comparator.comparing(UpdateJob::updateTime));
+    }
+
+    public synchronized void add(T key, Instant updateTime) {
+        updateQueue.add(new UpdateJob<>(key, updateTime));
+        notifyAll();
+    }
+
+    public synchronized T next() throws InterruptedException {
+        while (true) {
+            if (updateQueue.isEmpty()) {
+                wait(); // Wait for a new job to be added
+                continue;
+            }
+
+            UpdateJob<T, T2> job = updateQueue.peek();
+            Instant now = Instant.now();
+
+            if (job.updateTime.isAfter(now)) {
+                Duration toWait = Duration.between(now, job.updateTime);
+                wait(Math.max(1, toWait.toMillis()));
+            }
+            else {
+                updateQueue.poll(); // Remove the job from the queue since it's due
+                return job.key();
+            }
+        }
+    }
+
+    public synchronized void clear() {
+        updateQueue.clear();
+        notifyAll();
+    }
+
+    public synchronized void replaceQueue(Collection<UpdateJob<T,T2>> newJobs) {
+        updateQueue.clear();
+        updateQueue.addAll(newJobs);
+        notifyAll();
+    }
+}

code/processes/ping-process/java/nu/marginalia/ping/fetcher/PingDnsFetcher.java

@@ -3,6 +3,8 @@ package nu.marginalia.ping.fetcher;
 import com.google.inject.Inject;
 import com.google.inject.name.Named;
 import nu.marginalia.ping.model.SingleDnsRecord;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.xbill.DNS.ExtendedResolver;
 import org.xbill.DNS.Lookup;
 import org.xbill.DNS.TextParseException;
@@ -17,6 +19,7 @@ import java.util.concurrent.*;
 public class PingDnsFetcher {
     private final ThreadLocal<ExtendedResolver> resolver;
     private static final ExecutorService digExecutor = Executors.newFixedThreadPool(100);
+    private static final Logger logger = LoggerFactory.getLogger(PingDnsFetcher.class);
 
     private static final int[] RECORD_TYPES = {
             Type.A, Type.AAAA, Type.NS, Type.MX, Type.TXT,
@@ -25,8 +28,7 @@ public class PingDnsFetcher {
 
     @Inject
     public PingDnsFetcher(@Named("ping.nameservers")
-                      List<String> nameservers) throws UnknownHostException
-    {
+                      List<String> nameservers) {
         resolver = ThreadLocal.withInitial(() -> createResolver(nameservers));
     }
 
@@ -81,13 +83,12 @@ public class PingDnsFetcher {
                 try {
                     results.addAll(future.get(1, TimeUnit.MINUTES));
                 } catch (Exception e) {
-                    e.printStackTrace();
-                    System.err.println("Error fetching DNS records: " + e.getMessage());
+                    logger.error("Error fetching DNS records", e);
                 }
             }
         } catch (InterruptedException e) {
             Thread.currentThread().interrupt();
-            System.err.println("DNS query interrupted: " + e.getMessage());
+            logger.error("DNS query interrupted", e);
         }
         return results;
     }

code/processes/ping-process/java/nu/marginalia/ping/fetcher/PingHttpFetcher.java

@@ -83,7 +83,7 @@ public class PingHttpFetcher {
         } catch (SocketTimeoutException ex) {
             return new TimeoutResponse(ex.getMessage());
         } catch (IOException e) {
-            return new ConnectionError(e.getMessage());
+            return new ConnectionError(e.getClass().getSimpleName());
         }
     }
 

code/processes/ping-process/java/nu/marginalia/ping/io/HttpClientProvider.java

@@ -51,7 +51,7 @@ public class HttpClientProvider implements Provider<HttpClient> {
 
         connectionManager = PoolingHttpClientConnectionManagerBuilder.create()
                 .setMaxConnPerRoute(2)
-                .setMaxConnTotal(5000)
+                .setMaxConnTotal(50)
                 .setDefaultConnectionConfig(connectionConfig)
                 .setTlsSocketStrategy(
                         new DefaultClientTlsStrategy(SSLContext.getDefault(), NoopHostnameVerifier.INSTANCE))

code/processes/ping-process/java/nu/marginalia/ping/model/DomainAvailabilityRecord.java

@@ -70,6 +70,11 @@ implements WritableModel
         return millis == null ? null : Duration.ofMillis(millis);
     }
 
+    @Override
+    public Instant nextUpdateTime() {
+        return nextScheduledUpdate;
+    }
+
     @Override
     public void write(Connection connection) throws SQLException {
         try (var ps = connection.prepareStatement(

code/processes/ping-process/java/nu/marginalia/ping/model/DomainDnsRecord.java

@@ -60,6 +60,11 @@ public record DomainDnsRecord(
         return new Builder();
     }
 
+    @Override
+    public Instant nextUpdateTime() {
+        return tsNextScheduledUpdate;
+    }
+
     @Override
     public void write(Connection connection) throws SQLException {
 

code/processes/ping-process/java/nu/marginalia/ping/model/DomainSecurityEvent.java

@@ -16,6 +16,8 @@ public record DomainSecurityEvent(
         boolean certificateProfileChanged,
         boolean certificateSanChanged,
         boolean certificatePublicKeyChanged,
+        boolean certificateSerialNumberChanged,
+        boolean certificateIssuerChanged,
         Duration oldCertificateTimeToExpiry,
         boolean securityHeadersChanged,
         boolean ipChanged,
@@ -41,8 +43,10 @@ public record DomainSecurityEvent(
                 change_software,
                 old_cert_time_to_expiry,
                 security_signature_before,
-                security_signature_after
-                ) VALUES    (?,?,?,?,?,?,?,?,?,?,?,?,?,?)
+                security_signature_after,
+                change_certificate_serial_number,
+                change_certificate_issuer
+                ) VALUES    (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)
             """))
         {
 
@@ -75,6 +79,9 @@ public record DomainSecurityEvent(
                 ps.setBytes(14, securitySignatureAfter().compressed());
             }
 
+            ps.setBoolean(15, certificateSerialNumberChanged());
+            ps.setBoolean(16, certificateIssuerChanged());
+
             ps.executeUpdate();
         }
     }

code/processes/ping-process/java/nu/marginalia/ping/model/DomainSecurityRecord.java

@@ -203,7 +203,6 @@ public record DomainSecurityRecord(
             if (sslCertFingerprintSha256() == null) {
                 ps.setNull(12, java.sql.Types.BINARY);
             } else {
-                System.out.println(sslCertFingerprintSha256().length);
                 ps.setBytes(12, sslCertFingerprintSha256());
             }
             if (sslCertSan() == null) {

code/processes/ping-process/java/nu/marginalia/ping/model/HistoricalAvailabilityData.java

@@ -1,6 +1,13 @@
 package nu.marginalia.ping.model;
 
 public sealed interface HistoricalAvailabilityData {
+    public String domain();
+    record JustDomainReference(DomainReference domainReference) implements HistoricalAvailabilityData {
+        @Override
+        public String domain() {
+            return domainReference.domainName();
+        }
+    }
     record JustAvailability(String domain, DomainAvailabilityRecord record) implements HistoricalAvailabilityData {}
     record AvailabilityAndSecurity(String domain, DomainAvailabilityRecord availabilityRecord, DomainSecurityRecord securityRecord) implements HistoricalAvailabilityData {}
 }

code/processes/ping-process/java/nu/marginalia/ping/model/RootDomainReference.java

@@ -0,0 +1,6 @@
+package nu.marginalia.ping.model;
+
+public sealed interface RootDomainReference {
+    record ById(long id) implements RootDomainReference { }
+    record ByName(String name) implements RootDomainReference { }
+}

code/processes/ping-process/java/nu/marginalia/ping/model/WritableModel.java

@@ -1,8 +1,14 @@
 package nu.marginalia.ping.model;
 
+import javax.annotation.Nullable;
 import java.sql.Connection;
 import java.sql.SQLException;
+import java.time.Instant;
 
 public interface WritableModel {
      void write(Connection connection) throws SQLException;
+     @Nullable
+     default Instant nextUpdateTime() {
+            return null;
+     }
 }

code/processes/ping-process/java/nu/marginalia/ping/model/comparison/SecurityInformationChange.java

@@ -15,6 +15,8 @@ public record SecurityInformationChange(
         boolean isCertificateProfileChanged,
         boolean isCertificateSanChanged,
         boolean isCertificatePublicKeyChanged,
+        boolean isCertificateSerialNumberChanged,
+        boolean isCertificateIssuerChanged,
         Duration oldCertificateTimeToExpiry,
         boolean isSecurityHeadersChanged,
         boolean isIpAddressChanged,
@@ -30,8 +32,10 @@ public record SecurityInformationChange(
 
         boolean certificateFingerprintChanged = 0 != Arrays.compare(before.sslCertFingerprintSha256(), after.sslCertFingerprintSha256());
         boolean certificateProfileChanged = before.certificateProfileHash() != after.certificateProfileHash();
+        boolean certificateSerialNumberChanged = !Objects.equals(before.sslCertSerialNumber(), after.sslCertSerialNumber());
         boolean certificatePublicKeyChanged = 0 != Arrays.compare(before.sslCertPublicKeyHash(), after.sslCertPublicKeyHash());
         boolean certificateSanChanged =  !Objects.equals(before.sslCertSan(), after.sslCertSan());
+        boolean certificateIssuerChanged = !Objects.equals(before.sslCertIssuer(), after.sslCertIssuer());
 
         Duration oldCertificateTimeToExpiry = before.sslCertNotAfter() == null ? null : Duration.between(
                 Instant.now(),
@@ -50,6 +54,7 @@ public record SecurityInformationChange(
         boolean isChanged = asnChanged
                 || certificateFingerprintChanged
                 || securityHeadersChanged
+                || certificateProfileChanged
                 || softwareChanged;
 
         return new SecurityInformationChange(
@@ -59,6 +64,8 @@ public record SecurityInformationChange(
                 certificateProfileChanged,
                 certificateSanChanged,
                 certificatePublicKeyChanged,
+                certificateSerialNumberChanged,
+                certificateIssuerChanged,
                 oldCertificateTimeToExpiry,
                 securityHeadersChanged,
                 ipChanged,

code/processes/ping-process/java/nu/marginalia/ping/svc/DnsPingService.java

@@ -48,7 +48,6 @@ public class DnsPingService {
             switch (changes) {
                 case DnsRecordChange.None _ -> {}
                 case DnsRecordChange.Changed changed -> {
-                    logger.info("DNS record for {} changed: {}", newRecord.dnsRootDomainId(), changed);
                     generatedRecords.add(DomainDnsEvent.builder()
                             .rootDomainId(newRecord.dnsRootDomainId())
                             .nodeId(newRecord.nodeAffinity())

code/processes/ping-process/java/nu/marginalia/ping/svc/HttpPingService.java

@@ -18,6 +18,7 @@ import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.security.cert.X509Certificate;
 import java.sql.SQLException;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -75,8 +76,8 @@ public class HttpPingService {
 
             result = pingHttpFetcher.fetchUrl(url, Method.HEAD, null, null);
 
-            if (result instanceof HttpsResponse response && response.httpStatus() == 405) {
-                // If we get a 405, we try the GET method instead as not all servers support HEAD requests
+            if (result instanceof HttpsResponse response && shouldTryGET(response.httpStatus())) {
+                sleep(Duration.ofSeconds(2));
                 result = pingHttpFetcher.fetchUrl(url, Method.GET, null, null);
             }
             else if (result instanceof ConnectionError) {
@@ -84,8 +85,8 @@ public class HttpPingService {
                 if (!(result2 instanceof ConnectionError)) {
                     result = result2;
                 }
-                if (result instanceof HttpResponse response && response.httpStatus() == 405) {
-                    // If we get a 405, we try the GET method instead as not all servers support HEAD requests
+                if (result instanceof HttpResponse response && shouldTryGET(response.httpStatus())) {
+                    sleep(Duration.ofSeconds(2));
                     result = pingHttpFetcher.fetchUrl(alternateUrl, Method.GET, null, null);
                 }
             }
@@ -116,7 +117,7 @@ public class HttpPingService {
                         domainReference.nodeId(),
                         oldPingStatus,
                         ErrorClassification.CONNECTION_ERROR,
-                        null);
+                        rsp.errorMessage());
                 newSecurityInformation = null;
             }
             case TimeoutResponse rsp -> {
@@ -190,6 +191,29 @@ public class HttpPingService {
         return generatedRecords;
     }
 
+    private boolean shouldTryGET(int statusCode) {
+        if (statusCode < 400) {
+            return false;
+        }
+        if (statusCode == 429) { // Too many requests, we should not retry with GET
+            return false;
+        }
+
+        // For all other status codes, we can try a GET request, as many severs do not
+        // cope with HEAD requests properly.
+
+        return statusCode < 600;
+    }
+
+    private void sleep(Duration duration) {
+        try {
+            Thread.sleep(duration.toMillis());
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt(); // Restore the interrupted status
+            logger.warn("Sleep interrupted", e);
+        }
+    }
+
     private void comparePingStatuses(List<WritableModel> generatedRecords,
                                      DomainAvailabilityRecord oldPingStatus,
                                      DomainAvailabilityRecord newPingStatus) {
@@ -258,6 +282,8 @@ public class HttpPingService {
                 change.isCertificateProfileChanged(),
                 change.isCertificateSanChanged(),
                 change.isCertificatePublicKeyChanged(),
+                change.isCertificateSerialNumberChanged(),
+                change.isCertificateIssuerChanged(),
                 change.oldCertificateTimeToExpiry(),
                 change.isSecurityHeadersChanged(),
                 change.isIpAddressChanged(),

code/processes/ping-process/test/nu/marginalia/ping/PingDaoTest.java

@@ -318,6 +318,8 @@ class PingDaoTest {
                 true,
                 false,
                 true,
+                true,
+                false,
                 Duration.ofDays(30),
                 false,
                 false,
@@ -330,86 +332,6 @@ class PingDaoTest {
         svc.write(event);
     }
 
-    @Test
-    void getNextDomainPingStatuses() throws SQLException {
-        var svc = new PingDao(dataSource);
-
-        // Create a test domain availability record
-        var record = new DomainAvailabilityRecord(
-                1,
-                1,
-                true,
-                new byte[]{127, 0, 0, 1},
-                40,
-                0x0F00BA32L,
-                0x0F00BA34L,
-                HttpSchema.HTTP,
-                "etag123",
-                "Wed, 21 Oct 2023 07:28:00 GMT",
-                200,
-                "http://example.com/redirect",
-                Duration.ofMillis(150),
-                ErrorClassification.NONE,
-                "No error",
-                Instant.now().minus(30, ChronoUnit.SECONDS),
-                Instant.now().minus(3600, ChronoUnit.SECONDS),
-                Instant.now().minus(7200, ChronoUnit.SECONDS),
-                Instant.now().minus(3000, ChronoUnit.SECONDS),
-                2,
-                Duration.ofSeconds(60)
-        );
-
-        svc.write(record);
-
-        // Fetch the next domain ping statuses
-        var statuses = svc.getNextDomainPingStatuses(10, 1);
-        assertFalse(statuses.isEmpty());
-        assertEquals(1, statuses.size());
-    }
-
-    @Test
-    void getNextDnsDomainRecords() throws SQLException {
-        var svc = new PingDao(dataSource);
-
-        // Create a test DNS record
-
-        var dnsRecord = new DomainDnsRecord(null, "example.com", 2,
-                List.of("test"),
-                List.of("test2"),
-                "test3",
-                List.of("test4"),
-                List.of("test5"),
-                List.of("test6"),
-                List.of("test7"),
-                "test8",
-                Instant.now().minus(3600, ChronoUnit.SECONDS),
-                Instant.now().minus(3600, ChronoUnit.SECONDS),
-                4);
-
-        svc.write(dnsRecord);
-
-
-        var nextRecords = svc.getNextDnsDomainRecords(1, 2);
-
-        assertFalse(nextRecords.isEmpty());
-        assertEquals(1, nextRecords.size());
-
-    }
-
-    @Test
-    void getOrphanedDomains(){
-
-        var svc = new PingDao(dataSource);
-        var orphanedDomains = svc.getOrphanedDomains(1);
-        System.out.println(orphanedDomains);
-        assertTrue(orphanedDomains.contains(new DomainReference(1, 1, "www.marginalia.nu")));
-        assertFalse(orphanedDomains.isEmpty());
-
-        var orphanedRootDomains = svc.getOrphanedRootDomains(1);
-        System.out.println(orphanedRootDomains);
-        assertTrue(orphanedRootDomains.contains("marginalia.nu"));
-    }
-
     @Test
     void write() {
         var dnsEvent = new DomainDnsEvent(