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Dan Burkert commented on KUDU-2050: ----------------------------------- I don't think it's a good idea to treat a tablet that is de-facto offline as bootstrapping. This has the potential to greatly increase the window in which a tablet is under-replicated. I think longterm it's preferrable to over-replicate to 4 replicas, then kill off one as the node finally comes back. > Avoid peer eviction during block manager startup > ------------------------------------------------ > > Key: KUDU-2050 > URL: https://issues.apache.org/jira/browse/KUDU-2050 > Project: Kudu > Issue Type: Bug > Components: fs, tserver > Affects Versions: 1.4.0 > Reporter: Adar Dembo > Priority: Critical > > In larger deployments we've observed that opening the block manager can take > a really long time, like tens of minutes or sometimes even hours. This is > especially true as of 1.4 where the log block manager tries to optimize > on-disk data structures during startup. > The default time to Raft peer eviction is 5 minutes. If one node is restarted > and LBM startup takes over 5 minutes, or if all nodes are restarted and > there's over 5 minutes of LBM startup time variance across them, the "slow" > node could have all of its replicas evicted. Besides generating a lot of > unnecessary work in rereplication, this effectively "defeats" the LBM > optimizations in that it would have been equally slow (but more efficient) to > reformat the node instead. > So, let's reorder startup such that LBM startup counts towards replica > bootstrapping. One idea: adjust FsManager startup so that tablet-meta/cmeta > files can be accessed early to construct bootstrapping replicas, but to defer > opening of the block manager until after that time. -- This message was sent by Atlassian JIRA (v6.4.14#64029)