Fix data race in WAL #9580
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Fix data race in WAL #9580
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This commit fixes a data race in the WAL, which can occur when writes and deletes are being executed concurrently. The WAL uses a buffer pool of `[]byte` when reading the WAL. WAL entries are unmarshaled into these buffers and passed along to the relevant methods handling the different types of entry (write, delete etc). In the case of deletes, the keys that need to be deleted were being stored for later processing, however these keys were part of the backing array of initial buffer from the pool. As such, those keys could be written to at a future time when handling other parts of the WAL.
ghost
assigned 
Removing the executable bit looks unintentional and unrelated to the fix. |
jwilder
approved these changes
Mar 15, 2018
Merged
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Fixes #9577.
This PR fixes a data race in the WAL, which can occur when writes and deletes are being executed concurrently. The WAL uses a buffer pool of
[]bytewhen reading from the log. WAL entries are unmarshaled into these buffers and passed along to the relevant methods handling the differenttypes of entry (write, delete etc).
In the case of deletes, the keys that need to be deleted were being stored for later processing, however these keys were part of the backing array of initial buffer from the pool. As such, those keys could be written to at a future time when handling other parts of the WAL.
The original bug can be triggered as follows:
$ go test -c -race github.com/influxdata/influxdb/tsdb $ repeat 100 ./tsdb.test -test.run TestStore_SketchesIn
masterthe race should appear after a few iterations. I've ran a few hundred iterations on this PR and it's 🍏 📗 💚