## Speeding up pkgsrc builds with ccache and distcc

Building an important amount of packages with *pkgsrc* can take a very long time. Two helper softwares can speed up operations significantly: [ccache](http://ccache.samba.org/) and [distcc](http://code.google.com/p/distcc/).

### ccache

From package's DESCR:

*ccache is a compiler cache. It acts as a caching pre-processor
to C/C++ compilers, using the -E compiler switch and a hash to
detect when a compilation can be satisfied from cache. This
often results in a 5 to 10 times speedup in common compilations.*

Using *ccache* in *pkgsrc* is very simple, just add the following line to your */etc/mk.conf*:

	PKGSRC_COMPILER=	ccache gcc

Declaring *ccache* as a compiler in *mk.conf* will make it a dependency for every package to be built.

### distcc

From package's DESCR:

*distcc is a program to distribute compilation of C or C++ code across
several machines on a network. distcc should always generate the same
results as a local compile, is simple to install and use, and is often
two or more times faster than a local compile.*

We will setup *distcc* with two hosts called hostA and hostB. First, install the software on both machines:

	# cd /usr/pkgsrc/devel/distcc && make install clean
	# cp /usr/pkg/share/examples/rc.d/distccd /etc/rc.d

Configure some parameters in order to allow hostA and hostB to use each other's *distcc* instances. hostA's IP address is 192.168.1.1, hostB's IP address is 192.168.1.2:

	hostA$ grep distcc /etc/rc.conf
	distccd=YES
	distccd_flags="--allow 192.168.1.0/24 --allow 127.0.0.1 --listen 192.168.1.1 --log-file=/home/distcc/distccd.log"

	hostB$ grep distcc /etc/rc.conf
	distccd=YES
	distccd_flags="--allow 192.168.1.0/24 --allow 127.0.0.1 --listen 192.168.1.2 --log-file=/home/distcc/distccd.log"

Instead of sending logs to *syslog*, we will use a custom logfile located in *distcc*'s user home directory:

	# mkdir /home/distcc && chown distcc /home/distcc

We can then fire up *distcc* on both hosts:

	# /etc/rc.d/distccd start

In order to use hostnames instead of their IP addresses, add them to both */etc/hosts*:

	# tail -2 /etc/hosts
	192.168.1.1	hostA
	192.168.1.2	hostB

And finally tell *pkgsrc* to use *distcc* along with *ccache* by adding these lines to */etc/mk.conf* on both machines:

	PKGSRC_COMPILER=	ccache distcc gcc
	DISTCC_HOSTS=		hostA hostB
	MAKE_JOBS=		4

Here we define *MAKE_JOBS* to 4 because we are using two single-CPU hosts. The recommended value for *MAKE_JOBS* is *number of CPUs\*2* to avoid idle time.

### Testing

To see *distcc* in action, simply watch the */home/distcc/distccd.log* file while you are building a package:

	$ tail -f /home/distcc/distccd.log
	distccd[5218] (dcc_job_summary) client: 192.168.1.1:64865 COMPILE_OK exit:0 sig:0 core:0 ret:0 time:175ms gcc lockfile.c
	distccd[8292] (dcc_job_summary) client: 192.168.1.1:64864 COMPILE_OK exit:0 sig:0 core:0 ret:0 time:222ms gcc counters.c
	distccd[27779] (dcc_job_summary) client: 192.168.1.1:64881 COMPILE_OK exit:0 sig:0 core:0 ret:0 time:3009ms gcc ccache.c
	distccd[27779] (dcc_job_summary) client: 192.168.1.1:64863 COMPILE_OK exit:0 sig:0 core:0 ret:0 time:152ms gcc compopt.c