fixes CRDB watch implementation accumulating past updates #2100
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vroldanbet
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when the timestamp to start emitting updates from is way in the past, CRDB will not emit checkpoints. As a consequence, every update in the w.r.t to the moment the changefeed was created will accumulate in memory and OOM the process with a large enough backlog. The proposed solution is to compute one checkpoint from the real-time stream of updates, and then use that as the high-watermark for the backlog of changes from the past. We need to emit all the updates before we can emit a checkpoint, so downstream callers would have to handle it accordingly.
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superseded by #2120 |
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when the timestamp to start emitting updates from
is way in the past, CRDB will not emit checkpoints.
As a consequence, every update in the w.r.t to the moment the changefeed was created will accumulate
in memory and OOM the process with a large enough
backlog.
The proposed solution is to compute one checkpoint from the real-time stream of updates, and then use that as the high-watermark for the backlog of
changes from the past. We need to emit all the updates before we can emit a checkpoint, so downstream callers would have to handle it accordingly.