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Duo Zhang commented on HBASE-17449: ----------------------------------- I reviewed the usage of {{hbase.client.scanner.timeout.period}} and found that it is also used at server side. It is also used to expire scanner leases. And in the current implementation, a separated scan rpc timeout is useless because that, if we get a rpc timeout at client side, then usually we will get an OutOfOrderScannerException for the next call and it does not make any difference than UnknownScannerException. So a scan rpc timeout less than the scanner timeout(like operation timeout for other operations) is useless. Will open a new issue to discuss this. I think we need to reconsider the timeout configs for scan. Thanks. > Add explicit document on different timeout settings > --------------------------------------------------- > > Key: HBASE-17449 > URL: https://issues.apache.org/jira/browse/HBASE-17449 > Project: HBase > Issue Type: Improvement > Components: documentation > Reporter: Yu Li > > Currently we have more than one timeout settings, mainly includes: > * hbase.rpc.timeout > * hbase.client.operation.timeout > * hbase.client.scanner.timeout.period > And in latest branch-1 or master branch code, we will have two other > properties: > * hbase.rpc.read.timeout > * hbase.rpc.write.timeout > However, in current refguid we don't have explicit instruction on the > difference of these timeout settings (there're explanations for each > property, but no instruction on when to use which) > In my understanding, for RPC layer timeout, or say each rpc call: > * Scan (openScanner/next): controlled by hbase.client.scanner.timeout.period > * Other operations: > 1. For released versions: controlled by hbase.rpc.timeout > 2. For 1.4+ versions: read operation controlled by hbase.rpc.read.timeout, > write operation controlled by hbase.rpc.write.timeout, or hbase.rpc.timeout > if the previous two are not set. > And hbase.client.operation.timeout is a higher-level control counting retry > in, or say the overall control for one user call. > After this JIRA, I hope when users ask questions like "What settings I should > use if I don't want to wait for more than 1 second for a single > put/get/scan.next call", we could give a neat answer. -- This message was sent by Atlassian JIRA (v6.3.4#6332)