使用Redis Cluster作为会话处理程序时，它是否可能具有高可用性？

Question

We are trying to use Redis Cluster for storing session data using last version of phpredis, 2.2.5, downloaded from github repository the 19 Juin of 2015, configuring redis as sessions handler in php.ini configuraiton file.

We have 6 instances, three as masters and three as slaves and we have tested that storing and reading session data works.

However if we shutdown any master the following error is shown by our application:

Fatal error: Uncaught exception 'RedisException' with message 'Connection closed' in /users/ets01/lib/php/DEIN/class.PSASession.php:64 Stack trace: #0 /users/ets01/lib/php/DEIN/class.PSASession.php(64): session_start() #1 /users/ets01/lib/php/DEIN/class.PSAPage.php(102): PSASession->__construct() #2 /users/ets01/web/inc/class.APP2Page.php(11): PSAPage->__construct('b', 11) #3 /users/ets01/web/html/index.php(11): APP2Page->__construct() #4 {main} thrown in /users/ets01/lib/php/DEIN/class.PSASession.php on line 64

Fatal error: Uncaught exception 'RedisException' with message 'Connection closed' in [no active file]:0 Stack trace: #0 {main} thrown in [no active file] on line 0

Connection is closed, and cluster does not works as we would like to, we would like that connection is redone to another instance.

Does phpredis driver manage connections to the cluster? Does it provides automatically the chance of getting the value from another cluster instance?

Answer 1

We resolved the problems :-)

At the moment of creating the cluster we have to use the server IP instead of 127.0.0.1

redis-trib.rb create --replicas 1 10.68.10.201:7001 10.68.10.201:7002 10.68.10.201:7003 10.68.10.201:7004 10.68.10.201:7005 10.68.10.201:7006

Now setting and getting values in the cluster from a PHP script works.

Also, for using it as session handler we had to use 5.6 version of, for previous versions we have a "segmentation fault" error.