On 24/07/2015 7:49 p.m., Jens Offenbach wrote: > I have found something out... Hopefully, it helps to reproduce and solve the > issue. > > I got it working with a good download rate, but very high CPU usage on Squid > 3.3.8 and Squid 3.5.6. There seems to be problem with large files that get > cached on disk in combination with memory caching. When I use these settings, > memory usage of Squid grows step-by-step with 100% CPU usage and 500 KB/sec > download rate: > > # MEMORY CACHE OPTIONS > # > ----------------------------------------------------------------------------- > maximum_object_size_in_memory 1 GB > memory_replacement_policy heap LFUDA > cache_mem 4 GB > > # DISK CACHE OPTIONS > # > ----------------------------------------------------------------------------- > maximum_object_size 10 GB > cache_replacement_policy heap GDSF > cache_dir aufs /var/cache/squid3 25600 16 256 > > I decided to turn off memory caching completely and used the following > settings: > > # MEMORY CACHE OPTIONS > # > ----------------------------------------------------------------------------- > maximum_object_size_in_memory 0 GB > memory_replacement_policy heap LFUDA > cache_mem 0 GB > > # DISK CACHE OPTIONS > # > ----------------------------------------------------------------------------- > maximum_object_size 10 GB > cache_replacement_policy heap GDSF > cache_dir aufs /var/cache/squid3 25600 16 256 > > Now, I get stable and high download rates even on a cache miss. >
Damn. That gives me ~90% confidence its the mem_node walking as new 4KB chunks of memory are appended to the memory copy of the object. I would expect to see a reduced effect in 3.5 that kicks in around maximum_object_size_in_memory. Since the memory copies are now split into cache_mem objects, vs transients (disk cache only, or totally non-cacheable). With the transients getting their unnecessary in-memory sections pruned away regularly. Amos _______________________________________________ squid-users mailing list squid-users@lists.squid-cache.org http://lists.squid-cache.org/listinfo/squid-users
