CODEWITHSUNDEEP
loggingvarnish
Muneeb Nasir
Muneeb Nasir

Reputation: 2504

How to setup Varnish logging?

I want to get Varnish to log requests. I found the command varnishlog -a -w /var/log/varnish.log, but it does not log anything.

Then I found that Varnish does not write to log by default. However I am unable to find configuration options for logging.

Upvotes: 16

Views: 42200

Answers (5)

Mehdi Hamidi
Mehdi Hamidi

Reputation: 129

The files /etc/default/varnish* are deprecated in systems with systemd. just run these commands:

systemctl enable varnishncsa.service
systemctl start varnishncsa.service

you can also modify the daemon parameters in /lib/systemd/system/varnishncsa.service

Upvotes: 3

scones
scones

Reputation: 3345

Since i landed here and the suggested fixed did not help:

My varnishncsa.log was empty and the process was running.

It turned out, that i HAD TO specify the log format (any format).

As this insight in itself did not fix my init script, i fixed it using this strategy.

Upvotes: 1

Ketola
Ketola

Reputation: 2767

If you want to log HTTP requests in NCSA Common Log Format you need to use varnishncsa. On CentOS/RedHat, the Varnish RPM package includes a varnishncsa init script that you can use to start logging. By default it logs to logfile="/var/log/varnish/varnishncsa.log".

Additionally if you wish to serve several different hosts through a single Varnish install, you'll want to include the host name in the log as well. This can be accomplished with the following setting in /etc/sysconfig/varnishncsa

DAEMON_OPTS="$DAEMON_OPTS -F '%{Host}i %h %l %u %t \"%r\" %s %b \"%{Referer}i\" \"%{User-agent}i\"'"

Please note that the method described in the link by Anshu only logs the requests that are passed through by Varnish to the backend servers. Cache hit requests will never be recorded (before Varnish 5.0 - see below). Therefore the HTTPD logs gathered this way cannot be used for statistical analysis.

Update: As @VikrantPogula mentioned, as of Varnish 5.0 all client requests are logged - including cache hits. This is the default behavior, and can be switched on explicitly using the -c switch.

Upvotes: 24

mattnthat
mattnthat

Reputation: 309

Metrics in Varnish are a common area that people struggle with.

It's relatively easy to get some one off request metrics but overall tracking over time generally involves using varnishncsa. Here is a guide on Varnish installation that includes metric setup

Upvotes: 6

Vikrant Pogula
Vikrant Pogula

Reputation: 31

In response to Ketola's answer, you can have varnishncsa log even Cache hit requests, by passing the -c flag. This will allow you to use HTTPD logs to analyse stats.

Example : varnishncsa -c -a -w ~/varnish.log will write cache hit requests to the file in default NCSA format

Upvotes: 3

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