First of all, I want to say thank you to all revive community that makes possible an open source project like this.
Well, some times once a week or two, some times 0 times in a week... we get ALL the banners blank and the error is (debugging with firebug) error 500 internal server error. Revive control panel works fine
Now, we use Revive 3.2.0 (blanks happened with 3.0.7 too) in a Cluster: 1 IP Load Balancer + 3 apache server (php 5.3.3 with XCache and apache 2.2.15) + 1 mysql server (mysql 5.6.25) + NAS and we are serving about 1.000.000.000 impressions per month. The CPU usage in all apache servers is about 40-50% at the high traffic hour. The problem happened using cache files and using memcached.
Well, for example, today the problem ocurred two times. First time, I didn't realize and was fixed when maintenance cronjob run. Second time, I see the blanks, I run the maintenance manually and banners showed fine.
This is mysql operations zabbix graph when the problem ocurred https://www.dropbox.com/s/i2h1ct525ffadb5/Captura%20de%20pantalla%202015-07-01%2003.20.18.png?dl=0
Maintenance cron run every hour: 1 * * * * and takes about 5-10 minutes to finish.
As you can see in the graph, banners begin to show blank in the minute 30... there isn't other cronjob running at that time.
Maybe in the minute 10, when maintenance finish plus 20 minutes more from cache refresh? I don't know because when the problem happens and I run the maintenance, all works fine again. Anyway, I need to fix this asap.
Any ideas? Thanks