DBZ-277 Don't send per-row SQL warning messages to clients #7
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…ly normally, as WARNING messages are transmitted all the way to the client (i.e. are costly). In my case I have lots of tables with types that aren't yet understood by decoderbufs. These tables aren't being monitored, but because logical decoding works on the level of the entire database, not just the tables monitored, rows from them are still reaching decoderbufs, generating vast numbers of warnings "Encountered unknown typid..." Likewise, I have many unmonitored materialized views. Every row deleted when doing a concurrent refresh generates the warning "...no PK is present..." These warnings cause two types of trouble when they hit the debezium postgres connector: a memory leak and increased CPU usage. The memory leak is because the JDBC layer carefully preserves these warnings in a list, and the list is never being cleared (this should be fixed in the connector). As for the CPU usage, I don't fully understand why the processing time increases so much. It's normal that it should double, as there are twice as many packets to process (one warning for every row), but it seems to take way more than twice as long.
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@DuncanSands thanks for filing a JIRA and for submitting this PR.
Would you mind logging an issue for this? |
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These warnings cause two types of trouble when they hit the debezium postgres
connector: a memory leak and increased CPU usage. The memory leak is because
the JDBC layer carefully preserves these warnings in a list, and the list is
never being cleared (this should be fixed in the connector)
Would you mind logging an issue for this?
I opened DBZ-279 for this.
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Don't use the WARNING log level for situations that can occur perfectly normally, as WARNING messages are transmitted all the way to the client (i.e. are costly).
In my case I have lots of tables with types that aren't yet understood by
decoderbufs. These tables aren't being monitored, but because logical decoding
works on the level of the entire database, not just the tables monitored, rows
from them are still reaching decoderbufs, generating vast numbers of warnings
"Encountered unknown typid..."
Likewise, I have many unmonitored materialized views. Every row deleted when
doing a concurrent refresh generates the warning
"...no PK is present..."
These warnings cause two types of trouble when they hit the debezium postgres
connector: a memory leak and increased CPU usage. The memory leak is because
the JDBC layer carefully preserves these warnings in a list, and the list is
never being cleared (this should be fixed in the connector). As for the CPU
usage, I don't fully understand why the processing time increases so much.
It's normal that it should double, as there are twice as many packets to
process (one warning for every row), but it seems to take way more than twice
as long.