Fix unable to capture changes while concurrent writes #36
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Do we need to have a retry interval too? Can’t it just be the polling interval |
Yes, we can have the polling interval as the retry interval. The intention to introduce the retry interval was to reduce the waiting time and resume the process as quickly as possible. |
suhothayan
reviewed
Oct 18, 2019
| } | ||
| Thread.sleep((long) pollingInterval * 1000); | ||
| } catch (InterruptedException e) { | ||
| log.error("Error while polling. Current mode: " + CDCSourceConstants.MODE_POLLING, e); |
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Please improve the errors with the stream and App name information... else it will be hard to troubleshoot. please fix this for all cases.
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Fixed in b221509.
suhothayan
approved these changes
Oct 18, 2019
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Purpose
When concurrent/out-of-order writes for the auto-increment column occurs in the database, the source cannot capture such events in the polling mode.
Resolves #31
Goals
This PR introduces a strategy to handle such events by waiting on missing records.
Approach
When the
wait.on.missed.recordparameter is set totrue, the source expectspolling.columnvalues in (numeric) sequential order. For each record, the source generates an event. When reading and processing records in batches, if the source identifies a missed record it pauses the processing and waits until the missing record appears. If the missing record does not appear formissed.record.waiting.timeouttime period (in seconds), it ignores the record and resumes processing the rest.Security checks