Re: [squid-users] Poor cache

Hi,
Using version: Squid Cache: Version 3.1.10 (Centos RPM)

I also have this changes on the OS:

/etc/rc.local
/sbin/modprobe iptable_nat
/sbin/modprobe ip_nat_ftp
/sbin/modprobe ip_gre
/sbin/modprobe ip_conntrack
/sbin/modprobe ip_conntrack_ftp

echo 0 > /proc/sys/net/ipv4/tcp_syncookies
echo 131072 > /proc/sys/net/ipv4/tcp_max_syn_backlog
echo 524288 > /proc/sys/net/netfilter/nf_conntrack_max
echo 1 > /proc/sys/net/ipv4/ip_forward
echo 0 > /proc/sys/net/ipv4/conf/lo/rp_filter
modprobe iptable_nat
iptables -t nat -F PREROUTING
ip tunnel add gre0 mode gre remote 196.10.148.1 local 196.10.148.6 dev eth0
ip link set gre0 up

iptables -t nat -F
iptables -t nat -A PREROUTING -i gre0 -p tcp -m tcp --dport 80 -j DNAT
--to-destination 196.10.148.6:3401
touch /var/lock/subsys/local
~

/etc/sysctl.conf
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv4.ip_local_port_range = 1025 65535
fs.file-max = 372925
net.ipv4.tcp_max_syn_backlog = 2048
net.ipv4.tcp_syncookies = 1
net.ipv4.ip_forward = 1
# Controls source route verification
net.ipv4.conf.default.rp_filter = 0
net.ipv4.conf.eth0.rp_filter = 0
net.ipv4.conf.eth0.ip_filter = 0
net.ipv4.conf.gre0.rp_filter = 0
net.ipv4.conf.gre0.ip_filter = 0
net.ipv4.conf.default.accept_source_route = 1
# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0

# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1

# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 1

# Disable netfilter on bridges.
net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-arptables = 0

On 20 August 2014 09:50, Amos Jeffries <squid3_at_treenet.co.nz> wrote:
> On 20/08/2014 9:21 a.m., Délsio Cabá wrote:
>> Hi guys,
>> Need some help on cache. Basically I do not see many caches.
>>
>> root_at_c /]# cat /var/log/squid/access.log | awk '{print $4}' | sort |
>> uniq -c | sort -rn
>> 17403 TCP_MISS/200
>> 3107 TCP_MISS/304
>
> - objects in the client browser cache were used.
>
>> 1903 TCP_MISS/000
>
> - server was contacted but no response came back. This is bad. Seeing
> it in such numbers is very bad.
> It is a strong sign that TCP window scaling, ECN or ICMP blocking
> (Path-MTUd) issues are occuring on your traffic.
>
>
>> 1452 TCP_MISS/204
>
> - "204 no content" means there was no object to be cached.
>
>> 1421 TCP_MISS/206
>
> - Range request responses. Squid cannot cache these yet, but they
> should be cached in the client browser and contribute to those 304
> responses above.
>
>> 1186 TCP_MISS/302
>
> - along with the MISS/301, MISS/303 these are not cacheable without
> special instructions.
>
>> 659 TCP_MISS/503
>> 641 NONE/400
>> 548 TCP_MISS/301
>> 231 TCP_OFFLINE_HIT/200
>
> - cached object used.
>
>> 189 TCP_MISS/404
>> 126 TCP_IMS_HIT/304
>
> - cache object found, but objects in the client browser cache were used.
>
>> 112 TCP_MISS/504
>> 68 TCP_MISS/401
>> 56 TCP_MEM_HIT/200
>
> - cached object used.
>
>> 50 TCP_SWAPFAIL_MISS/304
>
> - cached object found, but disk error occurred loading it. And the
> client request was conditional. So object in client browser cache used
> instead.
>
>> 49 TCP_REFRESH_UNMODIFIED/200
>
> - cached objects found, mandatory update check required and resulted in
> Squid cached object being delivered to client.
>
>> 46 TCP_SWAPFAIL_MISS/200
>> 39 TCP_MISS/500
>> 36 TCP_MISS/502
>> 34 TCP_REFRESH_UNMODIFIED/304
>
> - cached objects found, mandatory update check required and resulted in
> client browser cache object being used.
>
>
>> 31 TCP_MISS/403
>> 25 TCP_MISS/400
>> 19 TCP_CLIENT_REFRESH_MISS/200
>
> - cached object found, but client request forced a new fetch.
>
>> 17 TCP_REFRESH_MODIFIED/200
>
> - cached object found, mandatory update check resulted in a new object
> being used.
>
>> 11 NONE/417
>> 9 TCP_MISS/303
>> 6 TCP_HIT/000
>
> - cached object used, but client disconnected before it could be delivered.
>
>> 5 TCP_MISS/501
>> 5 TCP_HIT/200
>
> - cached object used.
>
>> 4 TCP_MISS/202
>
> - this is usually only seen on POST or PUT. Which are not cacheable by
> Squid.
>
>> 3 TCP_MISS/412
>> 2 TCP_SWAPFAIL_MISS/000
>
> - cache object found, but disk error while loading it and the client
> disconnected before a server response was found.
>
>> 2 TCP_MISS/408
>> 1 TCP_MISS/522
>> 1 TCP_MISS/410
>> 1 TCP_MISS/405
>> 1 TCP_CLIENT_REFRESH_MISS/000
>
> - cached object found, but client request mandated an update check.
> Then client disconnected before that was completed.
>
>
>
> All the 4xx and 5xx status responses are only cacheable short term and
> only if the server explicitly provides caching information. It looks
> like the servers in your traffic are not providing that info (or not
> correctly).
>
>
> Also, this grep counting does not account for what method the
> transaction used. Things like the 204 response and 30x responses
> cacheability depend on what method is involved.
>
>
> So I see 19k MISS and 4k HIT. About 18% hit rate.
>
>
> What version of Squid are you using?
>
> Amos
Received on Wed Aug 20 2014 - 18:05:37 MDT