This commit fixes a deadlock that occurs during b1 flushes. It's
caused by taking locks in a different order. In the flush, b1
locks the engine and then bolt. However, in the query cursor, a
lock is obtained on bolt first (via `DB.Begin()`) and then the
engine is locked while reading from the engine's cache.
Getting an intermittent test failure with this so removing it for now since compactions
are still able to keep up without it. Will need to look into this further because the
allocations is still very high and will affect compactions over longer periods of time.
MergeIterator will be used to merge multiple TSM KeyIterators and the
WAL KeyIterator using a stream based iteration approach. Each iteration
cycle returns a key and values ordered in way to write a new TSM file
optimally.
This provides and interface and type to combine multiple WAL segments
in order and then allow the values to be read in an order suitable for
writing to a TSM file.
Starting to integrate some of the components into a engine that is
usable for development purposes. This allows the code to evolve while
keeping the existing TSM engine in tact for reference.
Currently, just the WAL is wired up so writes can be tested. Other engine
functions will panic the server if called.
This is the existing WAL + cache implementation. Moving it to a separate file
so that it can remain intact while a refactoring to a independent WAL can occur.
The WAL was also named Log in the code so this names file more closely to the concept
in the code.
This will faciliate loading a block into a type specific result without
first loading the block. This will also allow us to populate the database
index solely from the index.
There is a lot of allocations performed when decoding blocks. These
types can be re-used to reduce allocations in many cases. This change
allows a type specific slice to be passed in to decode funcs to be re-used
if it is large enough.
The existing decode is is left for backwards compatibility but is not
very efficient right now. It may be removed.
This writes a tombstone file containing a line per deleted key. This
file is read when a TSMReader is created and any keys listed in the file
are removed from the index.
This prevented the encoders from using other implementations of the Value
interface because it would always cast one of the types to our specific
implementations.
This adds some basic file reader/writers for creating the updated TSM file format. It uses a simple
in-memory index without MMAP for now, but will be extended to use and indirect indexing approach as well as MMAPed file access as described in the design doc.
This code is not integrated into the TSM engine yet
Go style -- and existing runtime stats -- do not use underscores, but
instead use camel case. This change makes the internal stats adhere to
that convention.
When a dataFile is deleted, the f file pointer is set to nil. Since deleting
a file happens asynchronously, code that had a reference when it was valid may
run when it's gone.
dataFile was not protected by a mutex which causes a data race and live
code and tests. filesAndLock used reflect.DeepEqual on a copy of dataFile
slices. reflect.DeepEqual appears to access unexported dataFile fields
which can't be protected. This was changed to use a equals func that will
require a mutex to be acquired.
The other issue was that many of the dataFile funcs access the mmap without
acquiring a lock. When a dataFile is deleted (possibly during rewriting),
reads from the mmap could return invalid data because references to the dataFile
are still in use by other goroutines.
Fixes#4534
Mainly for debugging as since this should not happen going forward. Since
there may be points with NaN already stored in the WAL, this is helpful for
troubleshooting panics.
Float values are not supported in the existing engine and the tsm1
engines. This changes NewPoint to return an error if a field value
contains a NaN field. It also allows us to validate fields to prevent
other unsupported types from sneaking in through other input plugins.
When a database is dropped, removing old segments returns an error
because the files are already gone. Using RemoveAll handles this
case more gracefully.
If a drop database is executed while writes are in flight, a panic
could occur because the WAL would fail to write to the DB dirs where
had been removed.
Partil fix for #4538
The Stat+Remove calls are unnecessary because Rename will replace
the destination file if it exist or not. There is no need to remove
the destination file before calling Rename.
Several places use os.Remove and check for os.ErrNotExist. os.Remove
does not return os.ErrNotExit, it returns a *PathError so these remove
calls will panic if the file does not exist.
Instead use os.RemoveAll that will not return an error if the file does
not exist.
Fixes#4545
* refactor compaction
* rework compaction cleanup logic to work with multiple resulting files
* ensure the uint64 number for a series key doesn't use 0 or MaxInt64 for sentinel values
Close acquired the cacheLock and writeLock in a different order than flush. If addToCache was also
running in a goroutine (acquiring cacheLock), a deadlock could happen.
panic: error opening new segment file for wal: open /var/folders/lj/vlbynqp52pxdxxlxx64j6bk80000gn/T/tsm1-test709000715/_00002.wal: no such file or directory
goroutine 8 [running]:
github.com/influxdb/influxdb/tsdb/engine/tsm1.(*Log).writeToLog(0xc820098500, 0x1, 0xc8201584b0, 0x1c, 0x45, 0x0, 0x0)
/Users/jason/go/src/github.com/influxdb/influxdb/tsdb/engine/tsm1/wal.go:427 +0xc19
When rewriting a tsm file, a panice on the Values slice could happen
if there were no values in the slice and the conditions of the rewrite
causes DecodeAndCombine to be called with the empty slice. This could
happen is the sizes of the points new values was equal to
the MaxPointsInBlock config options and there were no future blocks after
the current one being written.
When this happens, DecodeAndCombine returns a zero length remaining values
slice which is passed back into DecodeAndCombine one last time. In this case,
we now just return the original block since there is nothing new to combine.
Fixes#4444#4365
This will help large integer counters type fields that increment by
small amounts over time. Instead of storing the larger raw value
in a compressed format, we store the difference from the prior value
in compressed format which allows the value to be stored using
fewer bits.
influx_inpsect uncovered some scenarios where timestamps could be stored using
run-length encoding but were being stored using simple8 which uses more space.
If DecodeSameTypeBlock is called on on an empty Values slice, it would
panic with an index out of bounds error. This func can actually be removed
because DecodeBlock can determine what type of values are encoded already.
This will still panic if the block cannot be decoded due to other reasons.
Fixes#4365
If similar float values were encoded, the number of leading bits would
overflow the 5 available bits to store them (e.g. store 33 in 5 bits). When
decoding, the values after the overflowed value would spike to very large and
small values.
To prevent the overflow, we clamp the value to 31 which is the maximum
number of leading zero bits we can encoded.
Fixes#4357
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.
The defer tx.Rollback() tries to free the queryLock but the defer e.Cleanup() runs
before it and tries to take a write lock on the query lock (which blocks) and prevents
tx.Rollback() from acquring the read lock.
Previously were using a frame of reference approach where we would
transform the (possibly negative) deltas into positive values from
the minimum. That required an extra pass over the values as well
as a large slice allocation so we could encode the originals in uncompressed
form if they were too large.
This switches the encoding to use zigzag encoding for the deltas which
removes the extra slice allocation as well as the extra loops.
Improves encoding performane by ~4x.
This is using zig zag encoding to convert int64 to uint64s and then using simple8b
to compress them, falling back to uncompressed if the value exceeds 1 << 60. A
patched encoding scheme would likely be better in general but this provides decent
compression for integers that are not at the ends of the int64 range.
Time compression uses an adaptive approach using delta-encoding,
frame-of-reference, run length encoding as well as compressed integer
encoding.
Float compression uses an implementation of the Gorilla paper encoding
for timestamps based on XOR deltas and leading and trailing null suppression.
Jason Wilder
Philip O'Toole
Philip O'Toole
Ben Johnson
Jason Wilder
CrazyJvm
Paul Dix
Jason Wilder