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Keith Turner commented on ACCUMULO-1152: ---------------------------------------- Just had a realization, before a walog can be used it must be written to the metadata table. So its likely the metadata table check will prevent a tserver from getting new logs. But this check is just based on cache. If a tserver does see a metadata table write fail because it does not hold its lock, it should probably do something. > Add more sanity checks to limit the damage of multiple assignment > ----------------------------------------------------------------- > > Key: ACCUMULO-1152 > URL: https://issues.apache.org/jira/browse/ACCUMULO-1152 > Project: Accumulo > Issue Type: Improvement > Reporter: Keith Turner > Fix For: 1.6.0 > > > When an issue like ACCUMULO-954 comes along and causes a tablet to be hosted > on multiple tablet servers, its nice to have sanity checks that limit the > damage this can cause. > Accumulo already has a sanity check on writes to the metadata table that > ensures the tablet server making the write still holds a lock. This has > reliably triggered in cases of multiple assignment bugs. It would be nice to > have more checks like this. Below are some places I think checks would be > useful, are there more? > * Tserver attempts to positively check it holds its lock before getting a > new walog. > * Clients take some action to clear lockless tservers from their metadata > table cache. This would help prevent writing data to a zombie tserver that > may lose data, or reading stale data from a zombie tserver. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira