Details
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Bug
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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10.2(EOL), 10.3(EOL), 10.4(EOL), 10.5, 10.6
Description
With the following patch:
diff --git a/mysql-test/suite/mariabackup/xb_compressed_encrypted.opt b/mysql-test/suite/mariabackup/xb_compressed_encrypted.opt
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index 8baef973470..265ee9fe2e0 100644
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--- a/mysql-test/suite/mariabackup/xb_compressed_encrypted.opt
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+++ b/mysql-test/suite/mariabackup/xb_compressed_encrypted.opt
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@@ -1,5 +1,5 @@
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--innodb-encryption-rotate-key-age=2
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---innodb-encryption-threads=4
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+--innodb-encryption-threads=200
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--innodb-tablespaces-encryption
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--plugin-load-add=$FILE_KEY_MANAGEMENT_SO
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--loose-file-key-management |
and with the invocation
./mtr --start mariabackup.xb_compressed_encrypted
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I see high CPU usage on GNU/Linux on the 10.5 server. On the 10.6 server with MDEV-21452 fixed, the CPU usage is more moderate on GNU/Linux, but there is a huge amount of system calls. On Microsoft Windows, the changed system call pattern make the test run much slower, causing timeouts. This was successfully worked around by setting innodb_encryption_threads=1.
The anomaly is caused by the fact that fil_crypt_return_iops() is waking up all fil_crypt_thread even though innodb_encryption_rotate_key_age=0 and there is no work to do.
Unfortunately, for other settings than --innodb-encryption-rotate-key-age=0 a proper fix of this would require implementing a check whether the encryption plugin supports key versioning.
Attachments
Issue Links
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- Closed
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- Closed
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- Closed
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- Closed
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Activity
Develop the RQG test
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- grammar conf/mariadb/innodb_compression_encryption1.yy
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- setup conf/mariadb/innodb_compression_encryption2.cc
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in order to cover areas of functionality which are especially
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affected by MDEV-24426.
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Check that test+setup etc.
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For the record, on 10.6 ever since
MDEV-21452was fixed, the encryption threads employ pthread_cond_wait() without any timeout. Before that, the threads would wake up 10 times per second even if there is no work to do. On 10.6, I checked the following on Debian GNU/Linux:./mtr --start mariabackup.xb_compressed_encrypted &sudo powertopThe powertop main screen would report the wake-ups for each thread. I took 3 samples of the output while the server process that was started by mtr was idle. The biggest thread with wakeups was the timer_handler, which is used by InnoDB as well, ever since
MDEV-16264. That was 4.5 to 4.6 wakeups per second, in pthread_cond_timedwait(). I think that InnoDB should request 1.2 wakeups per second ever sinceMDEV-24280was fixed. No InnoDB threads were waking up during the measurement period, thanks to this fix (and the test now employing innodb_encryption_rotate_key_age=0) as well as the previous fixesMDEV-24278,MDEV-24270.Apart from the timer_handler, only two other threads were reported by powertop: ma_checkpoint_background (0.05 wakeups/second), and a random sample (0.00 wakeups/second) for tpool::thread_pool_generic::worker_main using a timed wait in tpool::thread_pool_generic::wait_for_tasks.