Measurement name and field were converted between []byte and string
repetively causing lots of garbage. This switches the code to use
[]byte in the write path.
Index.ForEachMeasurementTagKey held an RLock while call the fn,
if the fn made another call into the index which acquired an RLock
and after another goroutine tried to acquire a Lock, it would deadlock.
The lazy sorting of series caused a deadlock since it can not take
a Lock when a caller may have already acquired an RLock.
filters should be called w/o any locks as the function already acquires
locks as needed.
Removing series while trying to maintain the sorted series list
does not perform well when removing many series. This causes
drop DB, RP, series, to be very slow in some cases.
Instead, lazily create a sorted series list when first requested and
invalidate it when dropping series.
This code was added to address some slow startup issues. It is believed
to be the cause of some segfault panic's that occur at query time when
the underlying MMAP array has been unmapped. The current structure of
code makes this change unnecessary now.
If a bad query is run, kill query and limits would not kick in until
after it started executing. Some bad queries that involve high
cardinality can cause the server to OOM just from planning which
defeats the purpose of the max-select-series limit.
This change primarily fixes max-select-series limit so that the query
is killed earlier and has the side effect that kill query now can kill
a query while it's being planned.
The limit waited until all the iterators had been created which still
allows problem queries to be planned. This allows the queries to be
aborted much earlier in some cases.
Previously, tags had a `shouldCopy` flag to indicate if those tags
referenced an underlying buffer and should be copied to allow GC.
Unfortunately, this prevented tags from being copied that were
created and referenced the mmap which caused segfaults.
This change removes the `shouldCopy` flag and replaces it with a
`forceCopy` argument in `CreateSeriesIfNotExists()`. This allows
the write path to indicate that tags must be cloned on insert.
Adds a `tsdb.Series.ForEachTag()` function for safely iterating
over a series' tags within the context of a lock. This preverts
tags from being dereferenced during iteration which can cause
a seg fault.
This change delays Tag cloning until a new series is found, and will
only clone Tags acquired from `ParsePoints...` and not those referencing
the mmap-ed files (TSM) that are created on startup.
Stuart Carnie
Jason Wilder
Ben Johnson
Edd Robinson
Mark Rushakoff
Gunnar
Joe LeGasse
Mark Rushakoff