Although I have instructed php to only log an error once - i see the error over and over again in my log file. Any ideas why this directive would get ignored? I've restarted apache, etc.
This directive will only stop the error from being logged again within the same script run. When the same script is run multiple times, you will still see that error every time.
Besides the ignore_repeated_errors, there is also the ignore_repeated_source ini settings. I think that one would work for you and should stop showing the same error repeatedly, when same file is called over and over.
As PHP manual here says for it:
ignore_repeated_source- Ignore source of message when ignoring repeated messages. When this setting is On you will not log errors with repeated messages from different files or sourcelines
来源：https://stackoverflow.com/questions/1964732/php-log-will-not-ignore-repeated-errors-with-ignore-repeated-errors-on