[squid-users] Debugging slow access

[Steve Hill]

On 05.01.15 16:35, Eliezer Croitoru wrote:

> Can you share the "squid -v" output and the OS you are using?

Scientific Linux 6.6, see below for the squid -v output.

I've now more or less confirmed that this is the cause of my performance 
problems - every so often I see Squid using all the CPU whilst servicing 
very few requests.  Most of the CPU time is being used by the 
appendNewOnly() function.  For example, 228 milliseconds for 
appendNewOnly() to process a request with 2687 "token" notes attached to 
it, and this can happen more than once per request.


Squid Cache: Version 3.4.10
configure options:  '--build=x86_64-redhat-linux-gnu' 
'--host=x86_64-redhat-linux-gnu' '--target=x86_64-redhat-linux-gnu' 
'--program-prefix=' '--prefix=/usr' '--exec-prefix=/usr' 
'--bindir=/usr/bin' '--sbindir=/usr/sbin' '--sysconfdir=/etc' 
'--datadir=/usr/share' '--includedir=/usr/include' '--libdir=/usr/lib64' 
'--libexecdir=/usr/libexec' '--sharedstatedir=/var/lib' 
'--mandir=/usr/share/man' '--infodir=/usr/share/info' 
'--exec_prefix=/usr' '--libexecdir=/usr/lib64/squid' 
'--localstatedir=/var' '--datadir=/usr/share/squid' 
'--sysconfdir=/etc/squid' '--with-logdir=$(localstatedir)/log/squid' 
'--with-pidfile=$(localstatedir)/run/squid.pid' 
'--disable-dependency-tracking' '--enable-arp-acl' 
'--enable-follow-x-forwarded-for' '--enable-auth' 
'--enable-auth-basic-helpers=LDAP,MSNT,NCSA,PAM,SMB,YP,getpwnam,multi-domain-NTLM,SASL,DB,POP3,squid_radius_auth' 
'--enable-auth-ntlm-helpers=smb_lm,no_check,fakeauth' 
'--enable-auth-digest-helpers=password,ldap,eDirectory' 
'--enable-auth-negotiate-helpers=squid_kerb_auth' 
'--enable-external-acl-helpers=file_userip,LDAP_group,unix_group,wbinfo_group' 
'--enable-cache-digests' '--enable-cachemgr-hostname=localhost' 
'--enable-delay-pools' '--enable-epoll' '--enable-icap-client' 
'--enable-ident-lookups' '--enable-linux-netfilter' 
'--enable-referer-log' '--enable-removal-policies=heap,lru' 
'--enable-snmp' '--enable-ssl' '--enable-storeio=aufs,diskd,ufs,rock' 
'--enable-useragent-log' '--enable-wccpv2' '--enable-esi' '--with-aio' 
'--with-default-user=squid' '--with-filedescriptors=16384' '--with-dl' 
'--with-openssl' '--with-pthreads' 'build_alias=x86_64-redhat-linux-gnu' 
'host_alias=x86_64-redhat-linux-gnu' 
'target_alias=x86_64-redhat-linux-gnu' 'CFLAGS=-fPIE -Os -g -pipe 
-fsigned-char -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions 
-fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic' 
'LDFLAGS=-pie' 'CXXFLAGS=-fPIE -O2 -g -pipe -Wall 
-Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector 
--param=ssp-buffer-size=4 -m64 -mtune=generic' 
'PKG_CONFIG_PATH=/usr/lib64/pkgconfig:/usr/share/pkgconfig' 
--enable-ltdl-convenience


-- 
  - Steve Hill
    Technical Director
    Opendium Limited     http://www.opendium.com

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