Debezium server: v 1.9.0.Final
MongoDB Atlas: v 4.2.20
Running on AWS ECS with Fargate w/ 1GB CPU & 4GB MEMORY
Overview: Debezium starts an initial snapshot and it sends some data to kinesis but it runs into an error (below) before it finishes the snapshot. I've tried increasing the memory of the container to 4GB but not sure if that's the issue. The one collection I'm testing this with is 28GB total and 11M documents.
Debezium config (in Terraform):
environment = [
{
"name" : "DEBEZIUM_SINK_TYPE",
"value" : "kinesis"
},
{
"name" : "DEBEZIUM_SINK_KINESIS_REGION",
"value" : "us-east-1"
},
{
"name" : "DEBEZIUM_SINK_KINESIS_CREDENTIALS_PROFILE",
"value" : "default"
},
{
"name" : "DEBEZIUM_SINK_KINESIS_ENDPOINT",
"value" : "https://kinesis.us-east-1.amazonaws.com"
},
{
"name" : "DEBEZIUM_SOURCE_CONNECTOR_CLASS",
"value" : "io.debezium.connector.mongodb.MongoDbConnector"
},
{
"name" : "DEBEZIUM_SOURCE_OFFSET_STORAGE_FILE_FILENAME",
"value" : "data/offsets.dat"
},
{
"name" : "DEBEZIUM_SOURCE_OFFSET_FLUSH_INTERVAL_MS",
"value" : "0"
},
{
"name" : "DEBEZIUM_SOURCE_MONGODB_NAME",
"value" : "test"
},
{
"name" : "DEBEZIUM_SOURCE_MONGODB_HOSTS",
"value" : "test-mongodb-shard-00-00.test.mongodb.net:27017,test-mongodb-shard-00-01.test.mongodb.net:27017,test-mongodb-shard-00-02.test.mongodb.net:27017,test-mongodb-i-00-00.test.mongodb.net:27017"
},
{
"name" : "DEBEZIUM_SOURCE_MONGODB_SSL_ENABLED",
"value" : "true"
},
{
"name" : "DEBEZIUM_SOURCE_MONGODB_MEMBERS_AUTO_DISCOVER",
"value" : "true"
},
{
"name" : "DEBEZIUM_SOURCE_DATABASE_INCLUDE_LIST",
"value" : "test"
},
{
"name" : "DEBEZIUM_SOURCE_COLLECTION_INCLUDE_LIST",
"value" : "test.testCollection"
},
{
"name" : "DEBEZIUM_SOURCE_CAPTURE_MODE",
"value" : "change_streams_update_full"
},
{
"name" : "DEBEZIUM_SOURCE_DATABASE_HISTORY",
"value" : "io.debezium.relational.history.FileDatabaseHistory"
},
{
"name" : "DEBEZIUM_SOURCE_DATABASE_HISTORY_FILE_FILENAME",
"value" : "history.dat"
},
{
"name" : "QUARKUS_LOG_CONSOLE_JSON",
"value" : "false"
}
]
secrets = [
{
"name" : "DEBEZIUM_SOURCE_MONGODB_USER",
"valueFrom" : "${data.aws_secretsmanager_secret.test-debezium-read.arn}:username::"
},
{
"name" : "DEBEZIUM_SOURCE_MONGODB_PASSWORD",
"valueFrom" : "${data.aws_secretsmanager_secret.test-debezium-read.arn}:password::"
}
]
Stacktrace:
2022-06-01 18:22:23,976 ERROR [io.deb.con.mon.MongoDbSnapshotChangeEventSource] (debezium-mongodbconnector-test-replicator-snapshot-0) Error while attempting to sync 'test-mongodb-shard-0.test.testCollection': : java.lang.OutOfMemoryError: Java heap space
at java.base/java.util.Arrays.copyOf(Arrays.java:3745)
at java.base/java.lang.AbstractStringBuilder.ensureCapacityInternal(AbstractStringBuilder.java:172)
at java.base/java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:538)
at java.base/java.lang.StringBuffer.append(StringBuffer.java:317)
at java.base/java.io.StringWriter.write(StringWriter.java:106)
at org.bson.json.StrictCharacterStreamJsonWriter.write(StrictCharacterStreamJsonWriter.java:368)
at org.bson.json.StrictCharacterStreamJsonWriter.writeStartObject(StrictCharacterStreamJsonWriter.java:204)
at org.bson.json.LegacyExtendedJsonDateTimeConverter.convert(LegacyExtendedJsonDateTimeConverter.java:22)
at org.bson.json.LegacyExtendedJsonDateTimeConverter.convert(LegacyExtendedJsonDateTimeConverter.java:19)
at org.bson.json.JsonWriter.doWriteDateTime(JsonWriter.java:129)
at org.bson.AbstractBsonWriter.writeDateTime(AbstractBsonWriter.java:394)
at org.bson.codecs.DateCodec.encode(DateCodec.java:32)
at org.bson.codecs.DateCodec.encode(DateCodec.java:29)
at org.bson.codecs.EncoderContext.encodeWithChildContext(EncoderContext.java:91)
at org.bson.codecs.DocumentCodec.writeValue(DocumentCodec.java:203)
at org.bson.codecs.DocumentCodec.writeMap(DocumentCodec.java:217)
at org.bson.codecs.DocumentCodec.writeValue(DocumentCodec.java:200)
at org.bson.codecs.DocumentCodec.writeMap(DocumentCodec.java:217)
at org.bson.codecs.DocumentCodec.writeValue(DocumentCodec.java:200)
at org.bson.codecs.DocumentCodec.writeMap(DocumentCodec.java:217)
at org.bson.codecs.DocumentCodec.encode(DocumentCodec.java:159)
at org.bson.codecs.DocumentCodec.encode(DocumentCodec.java:46)
at org.bson.Document.toJson(Document.java:453)
at io.debezium.connector.mongodb.JsonSerialization.lambda$new$0(JsonSerialization.java:57)
at io.debezium.connector.mongodb.JsonSerialization$$Lambda$521/0x0000000840448840.apply(Unknown Source)
at io.debezium.connector.mongodb.JsonSerialization.getDocumentValue(JsonSerialization.java:89)
at io.debezium.connector.mongodb.MongoDbSchema$$Lambda$580/0x00000008404ce840.apply(Unknown Source)
at io.debezium.connector.mongodb.MongoDbCollectionSchema.valueFromDocumentOplog(MongoDbCollectionSchema.java:90)
at io.debezium.connector.mongodb.MongoDbChangeSnapshotOplogRecordEmitter.emitReadRecord(MongoDbChangeSnapshotOplogRecordEmitter.java:68)
at io.debezium.connector.mongodb.MongoDbChangeSnapshotOplogRecordEmitter.emitReadRecord(MongoDbChangeSnapshotOplogRecordEmitter.java:27)
at io.debezium.pipeline.AbstractChangeRecordEmitter.emitChangeRecords(AbstractChangeRecordEmitter.java:42)
at io.debezium.pipeline.EventDispatcher.dispatchSnapshotEvent(EventDispatcher.java:163)
I noticed that during the snapshot, the number of records sent and the last recorded offset doesn't seem to change while the amount of time elapsed between each of those messages gets longer. This seems like an exponential backoff thing but I'm not entirely sure.
Example:
2022-06-01 16:20:37,789 INFO [io.deb.con.mon.MongoDbSnapshotChangeEventSource] (debezium-mongodbconnector-test-replicator-snapshot-0) Beginning snapshot of 'test-mongodb-shard-0' at {sec=1654100437, ord=138, initsync=true, h=0}
2022-06-01 16:20:37,804 INFO [io.deb.con.mon.MongoDbSnapshotChangeEventSource] (debezium-mongodbconnector-test-replicator-snapshot-0) Exporting data for collection 'test-mongodb-shard-0.test.testCollection'
2022-06-01 16:20:42,983 INFO [io.deb.con.com.BaseSourceTask] (pool-7-thread-1) 717 records sent during previous 00:00:06.159, last recorded offset: {sec=1654100437, ord=138, initsync=true, h=0}
2022-06-01 16:20:57,417 INFO [io.deb.con.com.BaseSourceTask] (pool-7-thread-1) 2048 records sent during previous 00:00:14.434, last recorded offset: {sec=1654100437, ord=138, initsync=true, h=0}
2022-06-01 16:21:05,107 INFO [io.deb.con.mon.ReplicaSetDiscovery] (debezium-mongodbconnector-test-replica-set-monitor) Checking current members of replica set at test-mongodb-shard-00-00.test.mongodb.net:27017,test-mongodb-shard-00-01.test.mongodb.net:27017,test-mongodb-shard-00-02.test.mongodb.net:27017,test-mongodb-i-00-00.test.mongodb.net:27017
2022-06-01 16:21:16,624 INFO [io.deb.con.com.BaseSourceTask] (pool-7-thread-1) 2048 records sent during previous 00:00:19.207, last recorded offset: {sec=1654100437, ord=138, initsync=true, h=0}
2022-06-01 16:21:35,107 INFO [io.deb.con.mon.ReplicaSetDiscovery] (debezium-mongodbconnector-test-replica-set-monitor) Checking current members of replica set at test-mongodb-shard-00-00.test.mongodb.net:27017,test-mongodb-shard-00-01.test.mongodb.net:27017,test-mongodb-shard-00-02.test.mongodb.net:27017,test-mongodb-i-00-00.test.mongodb.net:27017
2022-06-01 16:21:53,130 INFO [io.deb.con.com.BaseSourceTask] (pool-7-thread-1) 2048 records sent during previous 00:00:36.505, last recorded offset: {sec=1654100437, ord=138, initsync=true, h=0}
2022-06-01 16:22:05,107 INFO [io.deb.con.mon.ReplicaSetDiscovery] (debezium-mongodbconnector-test-replica-set-monitor) Checking current members of replica set at test-mongodb-shard-00-00.test.mongodb.net:27017,test-mongodb-shard-00-01.test.mongodb.net:27017,test-mongodb-shard-00-02.test.mongodb.net:27017,test-mongodb-i-00-00.test.mongodb.net:27017
...
2022-06-01 16:23:17,521 INFO [io.deb.con.com.BaseSourceTask] (pool-7-thread-1) 2048 records sent during previous 00:01:24.391, last recorded offset: {sec=1654100437, ord=138, initsync=true, h=0}
2022-06-01 16:23:35,106 INFO [io.deb.con.mon.ReplicaSetDiscovery] (debezium-mongodbconnector-test-replica-set-monitor) Checking current members of replica set at test-mongodb-shard-00-00.test.mongodb.net:27017,test-mongodb-shard-00-01.test.mongodb.net:27017,test-mongodb-shard-00-02.test.mongodb.net:27017,test-mongodb-i-00-00.test.mongodb.net:27017
...
2022-06-01 16:26:06,523 INFO [io.deb.con.com.BaseSourceTask] (pool-7-thread-1) 2048 records sent during previous 00:02:49.003, last recorded offset: {sec=1654100437, ord=138, initsync=true, h=0}
2022-06-01 16:26:35,107 INFO [io.deb.con.mon.ReplicaSetDiscovery] (debezium-mongodbconnector-test-replica-set-monitor) Checking current members of replica set at test-mongodb-shard-00-00.test.mongodb.net:27017,test-mongodb-shard-00-01.test.mongodb.net:27017,test-mongodb-shard-00-02.test.mongodb.net:27017,test-mongodb-i-00-00.test.mongodb.net:27017
...
2022-06-01 16:31:18,075 INFO [io.deb.con.com.BaseSourceTask] (pool-7-thread-1) 2048 records sent during previous 00:05:11.552, last recorded offset: {sec=1654100437, ord=138, initsync=true, h=0}
2022-06-01 16:31:35,106 INFO [io.deb.con.mon.ReplicaSetDiscovery] (debezium-mongodbconnector-test-replica-set-monitor) Checking current members of replica set at test-mongodb-shard-00-00.test.mongodb.net:27017,test-mongodb-shard-00-01.test.mongodb.net:27017,test-mongodb-shard-00-02.test.mongodb.net:27017,test-mongodb-i-00-00.test.mongodb.net:27017
...
2022-06-01 16:42:07,711 INFO [io.deb.con.com.BaseSourceTask] (pool-7-thread-1) 2048 records sent during previous 00:10:49.636, last recorded offset: {sec=1654100437, ord=138, initsync=true, h=0}
2022-06-01 16:42:35,106 INFO [io.deb.con.mon.ReplicaSetDiscovery] (debezium-mongodbconnector-test-replica-set-monitor) Checking current members of replica set at test-mongodb-shard-00-00.test.mongodb.net:27017,test-mongodb-shard-00-01.test.mongodb.net:27017,test-mongodb-shard-00-02.test.mongodb.net:27017,test-mongodb-i-00-00.test.mongodb.net:27017
...
2022-06-01 17:03:12,872 INFO [io.deb.con.com.BaseSourceTask] (pool-7-thread-1) 2048 records sent during previous 00:21:05.161, last recorded offset: {sec=1654100437, ord=138, initsync=true, h=0}
2022-06-01 17:03:35,117 INFO [io.deb.con.mon.ReplicaSetDiscovery] (debezium-mongodbconnector-test-replica-set-monitor) Checking current members of replica set at test-mongodb-shard-00-00.test.mongodb.net:27017,test-mongodb-shard-00-01.test.mongodb.net:27017,test-mongodb-shard-00-02.test.mongodb.net:27017,test-mongodb-i-00-00.test.mongodb.net:27017
...
2022-06-01 17:45:58,637 INFO [io.deb.con.com.BaseSourceTask] (pool-7-thread-1) 2048 records sent during previous 00:42:45.765, last recorded offset: {sec=1654100437, ord=138, initsync=true, h=0}
2022-06-01 17:46:05,106 INFO [io.deb.con.mon.ReplicaSetDiscovery] (debezium-mongodbconnector-test-replica-set-monitor) Checking current members of replica set at test-mongodb-shard-00-00.test.mongodb.net:27017,test-mongodb-shard-00-01.test.mongodb.net:27017,test-mongodb-shard-00-02.test.mongodb.net:27017,test-mongodb-i-00-00.test.mongodb.net:27017
...
2022-06-01 18:22:23,976 ERROR [io.deb.con.mon.MongoDbSnapshotChangeEventSource] (debezium-mongodbconnector-test-replicator-snapshot-0) Error while attempting to sync 'test-mongodb-shard-0.test.testCollection': : java.lang.OutOfMemoryError: Java heap space
Beside increasing the container memory to 4GB , you can set also bigger heap size , the maximum and initial heap size can be set for example to 2GB :
If the issue continue follow this steps:
Start JVM with argument -XX:+HeapDumpOnOutOfMemoryError this will give you a heap dump when program goes in to OOM.
Use a tool like visualVM to analyze the heap dump obtained. That will help in identifying the memory leak.