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Mysql Server stuck with a long semaphore wait

infdude666infdude666 ContributorCurrent User Role Beginner
Today my server become unresponsive due to a long semaphore wait. From slow query logs i can see that commit, rollback and select(which usually takes 0.1sec) took abnormally large amount of time i.e more than 10sec max 5min

Im running Percona 5.5.32 x64

InnoDB: Warning: a long semaphore wait:
--Thread 1327466816 has waited at buf0flu.c line 1353 for 241.00 seconds the semaphore:
S-lock on RW-latch at 0x2ab01b59f1b0 '&block->lock'
a writer (thread id 1339287872) has reserved it in mode exclusive
number of readers 0, waiters flag 1, lock_word: 0
Last time read locked in file buf0flu.c line 1336
Last time write locked in file /mnt/workspace/percona-server-5.5-rpms/label_exp/centos5-64/target/BUILD/Percona-Server-5.5.32-rel31.0/storage/innobase/btr/btr0cur.c lin
e 306
InnoDB: ###### Starts InnoDB Monitor for 30 secs to print diagnostic info:
InnoDB: Pending preads 0, pwrites 0

=====================================
140405 23:21:51 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 26 seconds



mysql> show global variables like '%adaptive_hash_index%';
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| Variable_name | Value |
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| innodb_adaptive_hash_index | ON |
| innodb_adaptive_hash_index_partitions | 1 |
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Please help

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