I'm using AWS DMS to migrate one postgres db to another. I am performing a full load + ongoing replication task. The full load succeeded without issues for all of the schemas and their tables (around 120 tables). Some tables are being inserted into/updated (with acceptable latency) on the target db, but some are not. It's been 2 days of ongoing replication and one of my tables (relatively small ~800 records) has not been updated at all and has a record lag of around 3 records with replication latency of 2 days, while other tables (usually bigger) seem to have minimal record lag and replication latency closer to a couple hours.
Note that I am using a dms.r5.4xlarge replicator instance.
Is there a way to reduce record lag and replication latency for my tables/or perform replication in some sort of round robin fashion?
I'm using the following settings:
{
"Logging": {
"EnableLogging": true,
"LogComponents": [
{
"Severity": "LOGGER_SEVERITY_DEFAULT",
"Id": "TRANSFORMATION"
},
...
],
"CloudWatchLogGroup": "dms-tasks-temporary-analytics-replicator",
"CloudWatchLogStream": "dms-task-temporary-analytics-dms-v2"
},
"StreamBufferSettings": {
"StreamBufferCount": 3,
"CtrlStreamBufferSizeInMB": 5,
"StreamBufferSizeInMB": 8
},
"ErrorBehavior": {
"FailOnNoTablesCaptured": true,
"ApplyErrorUpdatePolicy": "LOG_ERROR",
"FailOnTransactionConsistencyBreached": false,
"RecoverableErrorThrottlingMax": 1800,
"DataErrorEscalationPolicy": "SUSPEND_TABLE",
"ApplyErrorEscalationCount": 0,
"RecoverableErrorStopRetryAfterThrottlingMax": true,
"RecoverableErrorThrottling": true,
"ApplyErrorFailOnTruncationDdl": false,
"DataTruncationErrorPolicy": "LOG_ERROR",
"ApplyErrorInsertPolicy": "LOG_ERROR",
"EventErrorPolicy": "IGNORE",
"ApplyErrorEscalationPolicy": "LOG_ERROR",
"RecoverableErrorCount": -1,
"DataErrorEscalationCount": 0,
"TableErrorEscalationPolicy": "STOP_TASK",
"RecoverableErrorInterval": 5,
"ApplyErrorDeletePolicy": "IGNORE_RECORD",
"TableErrorEscalationCount": 0,
"FullLoadIgnoreConflicts": true,
"DataErrorPolicy": "LOG_ERROR",
"TableErrorPolicy": "SUSPEND_TABLE"
},
"TTSettings": {
"TTS3Settings": null,
"TTRecordSettings": null,
"EnableTT": false
},
"FullLoadSettings": {
"CommitRate": 10000,
"StopTaskCachedChangesApplied": false,
"StopTaskCachedChangesNotApplied": false,
"MaxFullLoadSubTasks": 8,
"TransactionConsistencyTimeout": 600,
"CreatePkAfterFullLoad": false,
"TargetTablePrepMode": "DROP_AND_CREATE"
},
"TargetMetadata": {
"ParallelApplyBufferSize": 0,
"ParallelApplyQueuesPerThread": 0,
"ParallelApplyThreads": 0,
"TargetSchema": "",
"InlineLobMaxSize": 0,
"ParallelLoadQueuesPerThread": 0,
"SupportLobs": true,
"LobChunkSize": 0,
"TaskRecoveryTableEnabled": false,
"ParallelLoadThreads": 0,
"LobMaxSize": 102400,
"BatchApplyEnabled": false,
"FullLobMode": false,
"LimitedSizeLobMode": true,
"LoadMaxFileSize": 0,
"ParallelLoadBufferSize": 0
},
"BeforeImageSettings": null,
"ControlTablesSettings": {
"historyTimeslotInMinutes": 5,
"HistoryTimeslotInMinutes": 5,
"StatusTableEnabled": false,
"SuspendedTablesTableEnabled": false,
"HistoryTableEnabled": false,
"ControlSchema": "",
"FullLoadExceptionTableEnabled": false
},
"LoopbackPreventionSettings": null,
"CharacterSetSettings": null,
"FailTaskWhenCleanTaskResourceFailed": false,
"ChangeProcessingTuning": {
"StatementCacheSize": 50,
"CommitTimeout": 1,
"BatchApplyPreserveTransaction": true,
"BatchApplyTimeoutMin": 1,
"BatchSplitSize": 0,
"BatchApplyTimeoutMax": 30,
"MinTransactionSize": 1000,
"MemoryKeepTime": 60,
"BatchApplyMemoryLimit": 500,
"MemoryLimitTotal": 1024
},
"ChangeProcessingDdlHandlingPolicy": {
"HandleSourceTableDropped": true,
"HandleSourceTableTruncated": true,
"HandleSourceTableAltered": true
},
"PostProcessingRules": null
}