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https://issues.apache.org/jira/browse/HBASE-30519?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
ASF GitHub Bot updated HBASE-30519:
-----------------------------------
Labels: pull-request-available (was: )
> RegionReplicaFlushHandler aborts the region server when the table is dropped
> during its last flush attempt
> ----------------------------------------------------------------------------------------------------------
>
> Key: HBASE-30519
> URL: https://issues.apache.org/jira/browse/HBASE-30519
> Project: HBase
> Issue Type: Bug
> Reporter: Julian Chandra Sutadi
> Assignee: Julian Chandra Sutadi
> Priority: Major
> Labels: pull-request-available
>
> HBASE-29188 reported that region servers abort with
> {{TableNotFoundException}} after a table with region replicas is disabled and
> dropped. The issue was fixed by adding {{isTableDisabledOrDropped}} to
> {{{}RegionReplicaFlushHandler{}}}, so that a failed flush to the primary
> replica is ignored if the table is disabled or no longer exists.
> However, the catch block checks the flush error instead of the exception
> thrown by the {{isTableDisabled}} check. Since the method already returns
> early when the flush error is a {{{}TableNotFoundException{}}}, this branch
> can never be true:
> {code:java}
> // RegionReplicaFlushHandler.isTableDisabledOrDropped
> private boolean isTableDisabledOrDropped(IOException error, HRegion region) {
> if (error instanceof TableNotFoundException) { // error = the flush
> failure
> return true;
> }
> try {
> if
> (FutureUtils.get(connection.getAdmin().isTableDisabled(region.getRegionInfo().getTable())))
> {
> return true;
> }
> } catch (IOException e) { // e =
> TableNotFoundException once the table is dropped
> if (error instanceof TableNotFoundException) { // checks error instead
> of e, always false here
> return true;
> }
> ...
> }
> return false;
> }
> {code}
> After a drop, the flush itself fails with {{UnknownRegionException}} (the
> region is gone from meta), not {{TableNotFoundException}}, so the first check
> does not match either. As a result, {{isTableDisabledOrDropped}} returns
> false and the handler treats it as a normal flush failure:
> # If there are retries left, it sleeps and tries again. Before the next
> attempt, the while loop checks whether the secondary region is still open.
> Since disabling the table closed it, the loop exits and the handler finishes
> normally, so the bug has no visible effect.
> # If it was the last attempt, there is no retry and no next loop check. The
> flush error is rethrown and {{handleException}} aborts the region server.
> {code:java}
> // RegionReplicaFlushHandler.triggerFlushInPrimaryRegion
> while (!region.isClosing() && !region.isClosed() && ...) { // a closed
> secondary exits here on the next attempt
> ...
> } catch (IOException e) {
> if (isTableDisabledOrDropped(e, region)) {
> return;
> }
> if (!counter.shouldRetry()) {
> throw e; // last attempt:
> rethrown, handleException aborts the RS
> }
> ...
> }
> }
> {code}
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