Probably unrelated to your memory consumption: are you sure you want to authorize
twimg.com? I think that's the Twitter image server and I was not aware that Twitter was running PageSpeed. So if you authorize rewriting resources on that domain, and you reference one from your HTML, mod_pagespeed will happily fetch it, rewrite it, and change its URL to ".pagespeed." format, which will probably make
twimg.com respond with a 404.
RE memory consumption, there are two approaches I would take
- Decrease the amount of in-memory cache allocated by PageSpeed. See https://modpagespeed.com/doc/system for details. For such a small machine, I'd set "ModPagespeedLRUCacheKbPerProcess 0". You get 50MB in the shared-memory cache by default now, so that should be enough.
- Start paring down the set of filters that you enable until the memory. If you identify a specific filter you think might cause a problem, just disable it (and report a bug about that). From your list I'd start by disabling sprite_images. I was not aware that was a performance bottleneck, but that is a filter that by definition requires holding a bunch of images in-memory and operating on them.
Hope this helps!
-Josh