Description
I have been testing phpredis for performance and stability reasons. Performance is excellent , however I am seeing a repeatable stack trace error after sustained testing - running the same script via 'ab'.
Pattern is run this test 3 to 4 times
ab -n 10000 -c 10 -k "http://localhost:84/index.php?rw_app_id=1&code=test&device_id=test"
(If I run the request from a browser I cannot seem to get the error to appear, although that may because I cannot load the processes up.)
usually during the 3rd or 4th iteration the Apache error log reports the following:
Apache Error Log:
[warn] [client 127.0.0.1] mod_fcgid: stderr: PHP Fatal error: Uncaught exception 'RedisException' with message 'Redis server went away' in /var/www/web1/web/index.php:108
[warn] [client 127.0.0.1] mod_fcgid: stderr: Stack trace: [Wed Apr 18 16:39:49 2012] [warn] [client 127.0.0.1] mod_fcgid: stderr: #0 /var/www/web1/web/index.php(108): Redis->hGet('rw_promo_code:1...', 'unlock_code')
[warn] [client 127.0.0.1] mod_fcgid: stderr: #1 /var/www/web1/web/index.php(172): RedeemAPI->redeem()
[warn] [client 127.0.0.1] mod_fcgid: stderr: #2 {main}
[warn] [client 127.0.0.1] mod_fcgid: stderr: Next exception 'RedisException' with message 'Redis server went away' in /var/www/web1/web/index.php:0
[warn] [client 127.0.0.1] mod_fcgid: stderr: Stack trace:
[warn] [client 127.0.0.1] mod_fcgid: stderr: #0 /var/www/web1/web/index.php(172): Redis->__destruct()
[warn] [client 127.0.0.1] mod_fcgid: stderr: #1 /var/www/web1/web/index.php(172): RedeemAPI->redeem()
[warn] [client 127.0.0.1] mod_fcgid: stderr: #2 {main}
[warn] [client 127.0.0.1] mod_fcgid: stderr: thrown in /var/www/web1/web/index.php on line 0
[warn] [client 127.0.0.1] mod_fcgid: stderr: PHP Fatal error: Uncaught exception 'RedisException' with message 'Redis server went away' in /var/www/web1/web/index.php:108
[warn] [client 127.0.0.1] mod_fcgid: stderr: Stack trace:
[warn] [client 127.0.0.1] mod_fcgid: stderr: #0 /var/www/web1/web/index.php(108): Redis->hGet('rw_promo_code:1...', 'unlock_code')
[warn] [client 127.0.0.1] mod_fcgid: stderr: #1 /var/www/web1/web/index.php(172): RedeemAPI->redeem()
[warn] [client 127.0.0.1] mod_fcgid: stderr: #2 {main}
[warn] [client 127.0.0.1] mod_fcgid: stderr: Next exception 'RedisException' with message 'Redis server went away' in /var/www/web1/web/index.php:0
[warn] [client 127.0.0.1] mod_fcgid: stderr: Stack trace:
[warn] [client 127.0.0.1] mod_fcgid: stderr: #0 /var/www/web1/web/index.php(172): Redis->__destruct()
[warn] [client 127.0.0.1] mod_fcgid: stderr: #1 /var/www/web1/web/index.php(172): RedeemAPI->redeem()
[warn] [client 127.0.0.1] mod_fcgid: stderr: #2 {main}
[warn] [client 127.0.0.1] mod_fcgid: stderr: thrown in /var/www/web1/web/index.php on line 0
[warn] [client 127.0.0.1] mod_fcgid: stderr: PHP Fatal error: Uncaught exception 'RedisException' with message 'Redis server went away' in /var/www/web1/web/index.php:108
etc....
Restart Apache and Redis and can repeat the cycle. Occasionally it will connect again and process some requests successfully.
I can try catch the exception and try a reconnect however the processes does not recover.
Ubuntu x86_64 11.10 Redis Version 2.4 Apache/2.2.20 (Ubuntu) mod_fastcgi/mod_fastcgi-SNAP-0910052141 mod_fcgid/2.3.6 mod_perl/2.0.5 Perl/v5.12.4
Apologies - this was also posted at stackoverflow.com