In my last post I compared data at-rest encryption features available for MySQL and MariaDB. As noted at the time, some of the features available for Percona Server for MySQL were in development, and the latest version (5.7.23) sees two of them released as ALPHA quality.
Encrypting the InnoDB system tablespace
The first of the new features is InnoDB system tablespace encryption via innodb_sys_tablespace_encrypt, which …
[Read more]In this blog post, we’ll discuss the ins and outs of Percona Server 5.7 parallel doublewrite.
After implementing parallel LRU flushing as described in the previous post, we went back to benchmarking. At first, we tested with the doublewrite buffer turned off. We wanted to isolate the effect of the parallel LRU flusher, and the results validated the design. Then we turned the doublewrite buffer back on and saw very little, if any, gain from the parallel LRU flusher. What happened? Let’s take a look at the data:
We see that the doublewrite buffer mutex is gone as expected and that the top waiters are the rseg mutexes and the index lock (shouldn’t this be fixed in 5.7?). Then we checked PMP:
2678 nanosleep(libpthread.so.0),...,buf_LRU_get_free_block(buf0lru.cc:1435),... 867 pthread_cond_wait,...,log_write_up_to(log0log.cc:1293),... 396 …[Read more]