Amos: Thanks for the info. I am using workers so that explains why the output of mgr:info shows such a high number of file descriptors. If you don't mind I need some further clarification on the output of mgr:info. Just to summarize I have a global nofile limit of 8192 and the squid user is set to a soft limit of 4096 and a hard limit of 8192. The output of mgr:info contains a statistic "Largest file desc currently in use" (in my case it shows 3956). What exactly is that indicating? Would it be safe to assume that at some point in time a max of 3956 FD were in use (assuming each open FD is given a incrementing number)? Also, when squid first starts up it lists the Maximum number of file descriptors as 65536, but when I get the warning message that my Cache is low on FD that value changes to 16384. Why is that? Thanks On Wed, Jun 25, 2014 at 4:37 AM, Amos Jeffries <squid3@xxxxxxxxxxxxx> wrote: > On 25/06/2014 5:01 a.m., Matthew Ceroni wrote: >> Hi: >> >> I am running squid version 3.3.8 on CentOS v6.5. >> >> I have an issue regarding file descriptors. Our proxy has run into an >> issue the past few days (everyone streaming FIFA soccer I believe) >> where we receive the following error: >> >> WARNING! Your cache is running out of filedescriptors >> >> At this point the CPU usage of each squid worker spikes to 100% and >> the SNMP agent becomes unavailable. >> >> I was able to get some information from squidclient mgr:info. >> >> My question is around the file descriptor statistics: >> >> When the issue is happening it reports: >> >> File descriptor usage for squid: >> Maximum number of file descriptors: 16384 >> Largest file desc currently in use: 548 >> Number of file desc currently in use: 540 >> Files queued for open: 0 >> Available number of file descriptors: 15844 >> Reserved number of file descriptors: 100 >> Store Disk files open: 0 >> >> After a restart of squid it reports the following: >> >> File descriptor usage for squid: >> Maximum number of file descriptors: 65536 >> Largest file desc currently in use: 516 >> Number of file desc currently in use: 475 >> Files queued for open: 0 >> Available number of file descriptors: 65061 >> Reserved number of file descriptors: 400 >> Store Disk files open: 0 >> >> >> The ulimit setting for the OS is 8192 for open files. According to the >> documentation for max_filedescriptors (which I don't have set in my >> squid.conf) the default value is the ulimit value. Therefore why on >> first startup does it list the max FD of 65k? Also, when the issue >> arises why does it end up dropping to 16k? According to the output >> above there is at any point roughly only 1k FD in use, so why is squid >> reporting that it is running out of FD? >> > > On system startup the user initiating Squid is "root". The set of FD > limits applicable to root user are used. On later actions the proxy > low-privilege user account is used and a different set of limits apply > there. > The squid.conf directive value can be set if it is either smaller than > the limit the user account permits, OR if the user account has > permission to raise the value. > > There are also undetermined questions about whether there are bugs in > the logic finding the FD limit. > > > > PS. are you running with SMP workers? The 3.3 squid versions display FD > numbers summing the workers FD limits together and the log entry is made > if any one worker (or disker) reaches capacity. > > Amos
