Missing Deletions on Postgres CDC

gianniskod · March 22, 2023, 4:49pm

Is this your first time deploying Airbyte?: No
OS Version / Instance: Ubuntu 18.04.4 LTS
Memory / Disk: you can use something like 16Gb / 100GB
Deployment: Docker
Airbyte Version: 0.42.0
Source name/version: Postgres
Destination name/version: Snowflake
Step: During Sync
Description: Missing Deletions on CDC

Source Characteristics

Postgres Connector version : 1.0.51
Database Version : Aurora 12.04
replication_mothod: CDC
replication_plugin: pgoutput

Destination Characteristics

Snowflake Destination version: 0.4.53

Connection Characteristics

sync_mode: Incremental Deduped
streams: 1 Table
Replication frequency:
- 1st set of attempts: every 6 hours
- 2nd set of attempts: every 3 hours

Source Table Characteristics

Change Volume between syncs:
- 6-hours-syncs → [1.5GB, 2.5GB]
- 3-hours-syncs → [500MB, 1.5GB]
total volume: 5.5 GB

Problem Definition
we have detected that the table that we are syncing with the above-described setup and characteristics, misses some deletions.

This table accepts plenty of updates and deletions and inserts every hour, and that is the reason why the change volume on every sync can grow that much. One of our subsequent DBT transformations that use the deduped table failed in some uniqueness tests over a combined unique id.

After comparing both the deduped table in Snowflake and the source table in Postgres we identified that the prior one had some extra rows from the posterior. Furthermore, we double-checked it with the scd table, and there was no tracked deletion either on it.
This behavior increased on the latter syncs.

We want to understand if it is an expected behavior due to the heavy load of every sync or due to the replication slot failing to retrieve some of the changes.

Extra Hints

We have faced this issue with the below Postgres Connectors versions
- v1.0.23
- v1.0.51
We have tried it also with the new Postgres Connector version of 2.0.3 but CDC was not working so we rolled back to 1.0.51.
After changing the sync frequency to 3 hours from 6, we starting facing the same problem much faster than before.
The only Error that we are getting back without interrupting the sync process is

ERROR i.d.r.TableSchemaBuilder(lambda$createValueGenerator$5):302 Failed to properly convert data value for 'column_1' of type _varchar for row [masked_value, masked_value,masked_value, masked_value, java.lang.Object@21ebb339, masked_value, 0.0000, masked_value, masked_value, masked_value, null, null, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, java.lang.Object@21ebb339, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value, masked_value]: org.apache.kafka.connect.errors.DataException: Invalid Java object for schema with type ARRAY: class java.lang.String for field: "column_1"
	at org.apache.kafka.connect.data.ConnectSchema.validateValue(ConnectSchema.java:242) ~[connect-api-3.2.0.jar:?]
	at org.apache.kafka.connect.data.Struct.put(Struct.java:216) ~[connect-api-3.2.0.jar:?]
	at io.debezium.relational.TableSchemaBuilder.lambda$createValueGenerator$5(TableSchemaBuilder.java:298) ~[debezium-core-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.relational.TableSchema.valueFromColumnData(TableSchema.java:141) ~[debezium-core-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.relational.RelationalChangeRecordEmitter.emitUpdateRecord(RelationalChangeRecordEmitter.java:102) ~[debezium-core-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.relational.RelationalChangeRecordEmitter.emitChangeRecords(RelationalChangeRecordEmitter.java:53) ~[debezium-core-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.connector.postgresql.PostgresChangeRecordEmitter.emitChangeRecords(PostgresChangeRecordEmitter.java:96) ~[debezium-connector-postgres-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.pipeline.EventDispatcher.dispatchDataChangeEvent(EventDispatcher.java:209) ~[debezium-core-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.connector.postgresql.PostgresStreamingChangeEventSource.lambda$processMessages$0(PostgresStreamingChangeEventSource.java:275) ~[debezium-connector-postgres-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.connector.postgresql.connection.pgoutput.PgOutputMessageDecoder.decodeUpdate(PgOutputMessageDecoder.java:465) ~[debezium-connector-postgres-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.connector.postgresql.connection.pgoutput.PgOutputMessageDecoder.processNotEmptyMessage(PgOutputMessageDecoder.java:194) ~[debezium-connector-postgres-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.connector.postgresql.connection.AbstractMessageDecoder.processMessage(AbstractMessageDecoder.java:33) ~[debezium-connector-postgres-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.connector.postgresql.connection.PostgresReplicationConnection$1.deserializeMessages(PostgresReplicationConnection.java:510) ~[debezium-connector-postgres-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.connector.postgresql.connection.PostgresReplicationConnection$1.readPending(PostgresReplicationConnection.java:502) ~[debezium-connector-postgres-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.connector.postgresql.PostgresStreamingChangeEventSource.processMessages(PostgresStreamingChangeEventSource.java:215) ~[debezium-connector-postgres-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.connector.postgresql.PostgresStreamingChangeEventSource.execute(PostgresStreamingChangeEventSource.java:177) ~[debezium-connector-postgres-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.connector.postgresql.PostgresStreamingChangeEventSource.execute(PostgresStreamingChangeEventSource.java:41) ~[debezium-connector-postgres-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.pipeline.ChangeEventSourceCoordinator.streamEvents(ChangeEventSourceCoordinator.java:174) ~[debezium-core-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.pipeline.ChangeEventSourceCoordinator.executeChangeEventSources(ChangeEventSourceCoordinator.java:141) ~[debezium-core-1.9.6.Final.jar:1.9.6.Final]
	at io.debezium.pipeline.ChangeEventSourceCoordinator.lambda$start$0(ChangeEventSourceCoordinator.java:109) ~[debezium-core-1.9.6.Final.jar:1.9.6.Final]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539) ~[?:?]
	at java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[?:?]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) ~[?:?]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[?:?]
	at java.lang.Thread.run(Thread.java:833) ~[?:?]

Stack Trace: org.apache.kafka.connect.errors.DataException: Invalid Java object for schema with type ARRAY: class java.lang.String for field: "column_1"
	at org.apache.kafka.connect.data.ConnectSchema.validateValue(ConnectSchema.java:242)
	at org.apache.kafka.connect.data.Struct.put(Struct.java:216)
	at io.debezium.relational.TableSchemaBuilder.lambda$createValueGenerator$5(TableSchemaBuilder.java:298)
	at io.debezium.relational.TableSchema.valueFromColumnData(TableSchema.java:141)
	at io.debezium.relational.RelationalChangeRecordEmitter.emitUpdateRecord(RelationalChangeRecordEmitter.java:102)
	at io.debezium.relational.RelationalChangeRecordEmitter.emitChangeRecords(RelationalChangeRecordEmitter.java:53)
	at io.debezium.connector.postgresql.PostgresChangeRecordEmitter.emitChangeRecords(PostgresChangeRecordEmitter.java:96)
	at io.debezium.pipeline.EventDispatcher.dispatchDataChangeEvent(EventDispatcher.java:209)
	at io.debezium.connector.postgresql.PostgresStreamingChangeEventSource.lambda$processMessages$0(PostgresStreamingChangeEventSource.java:275)
	at io.debezium.connector.postgresql.connection.pgoutput.PgOutputMessageDecoder.decodeUpdate(PgOutputMessageDecoder.java:465)
	at io.debezium.connector.postgresql.connection.pgoutput.PgOutputMessageDecoder.processNotEmptyMessage(PgOutputMessageDecoder.java:194)
	at io.debezium.connector.postgresql.connection.AbstractMessageDecoder.processMessage(AbstractMessageDecoder.java:33)
	at io.debezium.connector.postgresql.connection.PostgresReplicationConnection$1.deserializeMessages(PostgresReplicationConnection.java:510)
	at io.debezium.connector.postgresql.connection.PostgresReplicationConnection$1.readPending(PostgresReplicationConnection.java:502)
	at io.debezium.connector.postgresql.PostgresStreamingChangeEventSource.processMessages(PostgresStreamingChangeEventSource.java:215)
	at io.debezium.connector.postgresql.PostgresStreamingChangeEventSource.execute(PostgresStreamingChangeEventSource.java:177)
	at io.debezium.connector.postgresql.PostgresStreamingChangeEventSource.execute(PostgresStreamingChangeEventSource.java:41)
	at io.debezium.pipeline.ChangeEventSourceCoordinator.streamEvents(ChangeEventSourceCoordinator.java:174)
	at io.debezium.pipeline.ChangeEventSourceCoordinator.executeChangeEventSources(ChangeEventSourceCoordinator.java:141)
	at io.debezium.pipeline.ChangeEventSourceCoordinator.lambda$start$0(ChangeEventSourceCoordinator.java:109)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.lang.Thread.run(Thread.java:833)

marcosmarxm · March 22, 2023, 7:03pm

Hello there! You are receiving this message because none of your fellow community members has stepped in to respond to your topic post. (If you are a community member and you are reading this response, feel free to jump in if you have the answer!) As a result, the Community Assistance Team has been made aware of this topic and will be investigating and responding as quickly as possible.
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gianniskod · March 30, 2023, 12:36pm

Is there anyone that could help us?
We have faced the same issue with another connection.

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