This reduces some of the lock contention when writing to the cache.
When a new entry is created, it avoids an allocation. It also skips
a check to see if we need to sorted if we already know it needs to sorted.
Parsing the line protocol again on the receiving side of the remote
write consumes a lot cpu. This uses a different marshaling format
that is much faster to parse after we already parsed the point on
the write side.
The history file is cleared before WriteHistory is called after each
command/exit() to prevent exponential file growth.
This commit addresses issue #5436, please see PR for full explanation.
Under highly conncurrent write load, the coordinating node would
create a connection to any other node that is part of the replica
group. Since each connection can be expensive, OOM sitations could
occur because there was no bounds on the number of new connections
that would be created. If writes on a remote node were slow, connections
could pile up an exacerbate the problem.
This switches the pool to be bounded and has a checkout that is blocking
with a timeout. If a connection is available, it's returned immediately.
If the pool still has room for more connections, it will create one if needed.
Otherwise, the call will block until a connection becomes available or
the timeout expires. In the case of a timeout, it is propogated back up
to the PointsWriter that determine what do return to the client.
Writing the snapshot would deduplicate the snapshot points
while still holding the engine write-lock. This can be expensive
under high load and cause writes to back up and OOM the server.
Instead, grab the snapshot under the lock and dedup it after releasing
the lock.
Possible fix for #5442
Possible fix for #5437. meta.Client.RetentionPolicy acquired a read-lock and
then called Database which called data() which acquired a read-lock again.
If a write lock was taken between these two read-locks (likely by Authenticate),
the write-lock would block, and the second read-lock would also block
causing a dead-lock.
Cory LaNou
joelegasse
Jason Wilder
Jason Wilder
Todd Persen
Ben Johnson
Adam Svoboda
Todd Persen
David Norton