I believe this change address the issues with hinted-handoff not fully replicating all data to nodes that come back online after an outage.. A detailed explanation follows.
During testing of of hinted-handoff (HH) under various scenarios, HH stats showed that the HH Processor was occasionally encountering errors while unmarshalling hinted data. This error was not handled completely correctly, and in clusters with more than 3 nodes, this could cause the HH service to stall until the node was restarted. This was the high-level reason why HH data was not being replicated.
Furthermore by watching, at the byte-level, the hinted-handoff data it could be seen that HH segment block lengths were getting randomly set to 0, but the block data itself was fine (Block data contains hinted writes). This was the root cause of the unmarshalling errors outlined above. This, in turn, was tracked down to the HH system opening each segment file multiple times concurrently, which was not file-level thread-safe, so these mutiple open calls were corrupting the file.
Finally, the reason a segment file was being opened multiple times in parallel was because WriteShard on the HH Processor was checking for node queues in an unsafe manner. Since WriteShard can be called concurrently this was adding queues for the same node more than once, and each queue-addition results in opening segment files.
This change fixes the locking in WriteShard such the check for an existing HH queue for a given node is performed in a synchronized manner.
Closing the store did not properly return an error for in-flight
writes because the closing channel was set to nil when closed. A
nil channel is not selectable so writes continue on past the guard
checks and trigger panics.
Will make it less error-prone to add new encodings int the future
since each encoder has it's set of constants. There are some placeholder
contants for uncompressed encodings which are not in all encoder currently.
* Fix bug with locking when the interval completely covers or is totally inside another one.
* Fix bug with full compactions running when the index is actively being written to.
If reading into fixed sized buffer using io.ReadFull, the func can
return io.ErrUnexpectedEOF if the read was short. This was slipping
through the error handling causing the shard to fail to load.
Philip O'Toole
Philip O'Toole
Cameron Sparr
Michael Desa
Nathaniel Cook
Paul Dix
Jason Wilder
Nathaniel Cook
Konstantin Shaposhnikov
Samer Kanjo
dgnorton
Paris Holley