Showing entries 1 to 2
Displaying posts with tag: sync_binlog (reset)
MySQL 5.7 By Default 1/3rd Slower Than 5.6 When Using Binary Logs

Researching a performance issue, we came to a startling discovery:

MySQL 5.7 + binlogs is by default 37-45% slower than MySQL 5.6 + binlogs when otherwise using the default MySQL settings

Test server MySQL versions used:
i7, 8 threads, SSD, Centos 7.2.1511

mysqld –options:

--no-defaults --log-bin=mysql-bin --server-id=2

Run details:
Sysbench version 0.5, 4 threads, socket file connection

Sysbench Prepare: 

sysbench --test=/usr/share/doc/sysbench/tests/db/parallel_prepare.lua --oltp-auto-inc=off --mysql-engine-trx=yes --mysql-table-engine=innodb --oltp_table_size=1000000 --oltp_tables_count=1 --mysql-db=test --mysql-user=root --db-driver=mysql --mysql-socket=/path_to_socket_file/your_socket_file.sock prepare …
[Read more]
Dealing with Assertion failure in log/log0recv.c – !page || (ibool)!!page_is_comp(page) == dict_table_is_comp(index->table)

This is a somewhat uncommon error, so I wanted to take a moment and post the error and an explanation in order to make it easier for those who run into this in the future.

The main error is this (full pasted below):

InnoDB: Assertion failure in thread 139838283589376 in file log/log0recv.c line 1094
InnoDB: Failing assertion: !page || (ibool)!!page_is_comp(page) == dict_table_is_comp(index->table)

Basically, this is what it can look like after a power outage. In fact, this is the only time I have seen it, but I won’t say that it is the only way you could encounter it.

How do I deal with this, you ask?

Well, the above error shows that the internal InnoDB dictionary is corrupt.

Unfortunately, in this situation, you must recreate the tablespace. And if you don’t have a current backup + binlogs, then that means you will also need to …

[Read more]
Showing entries 1 to 2