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Displaying posts with tag: show full processlist (reset)

Using SHOW PROCESSLIST and mysqladmin debug Output in Conjunction with SHOW INNODB STATUS
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When InnoDB appears hung, I know the natural reaction is to check SHOW ENGINE INNODB STATUS.

In fact, it’s the first thing I check when InnoDB tables are involved.

However, I just want to iterate how valuable SHOW FULL PROCESSLIST and/or mysqladmin debug outputs can be even when it seems mysqld is hung on on InnoDB table.

Two recent cases I’ve encountered illustrate why.

Case #1:

MySQL appeared hung on the following simple, single-row INSERT:

---TRANSACTION 0 2035648699, ACTIVE 76629 sec, process no 9047,
OS thread id 3069426592, thread declared inside InnoDB 500
mysql tables in use 1, locked 1
...
INSERT INTO test (id, parent, text) …
  [Read more...]
Advanced InnoDB Deadlock Troubleshooting – What SHOW INNODB STATUS Doesn’t Tell You, and What Diagnostics You Should be Looking At
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One common cause for deadlocks when using InnoDB tables is from the existence of foreign key constraints and the shared locks (S-lock) they acquire on referenced rows.

The reason I want to discuss them though is because they are often a bit tricky to diagnose, especially if you are only looking at the SHOW ENGINE INNODB STATUS output (which might be a bit counter-intuitive since one would expect it to contain this info).

Let me show a deadlock error to illustrate (below is from SHOW ENGINE INNODB STATUS\g):

------------------------
LATEST DETECTED DEADLOCK
------------------------
111109 20:10:03
*** (1) TRANSACTION:
TRANSACTION 65839, ACTIVE 19 sec, OS thread id 4264 …
  [Read more...]
Why You Want to Switch to MySQL 5.1
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In two words: online operations. In a paragraph: Forget partitioning, row-based replication and events. The big reasons most people are going to salivate over 5.1, and probably start plans to upgrade now, are the online operations:

  [Read more...]
Showing entries 1 to 3

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