一、介绍

rrdcached是一个高性能的RRD缓存守护进程，在不带来大量磁盘读/写文件i/o负荷的情况下，允许gmetad实例维护多个RRD文件。rrdcached可通过命令套接字控制，并且包含在大多数linux版本的标准rrdtool安装包中。

但是版本有要求，1.4.1以上的rrdtool已包含rrdcached，redhat6自带的是1.3.8的，如果使用，需要升级版本

二、编译安装包

rrdtool编译依赖包

cairo-devel is needed by rrdtool-1.4.7-1.el6.x86_64

freetype-devel is needed by rrdtool-1.4.7-1.el6.x86_64

gcc-c++ is needed by rrdtool-1.4.7-1.el6.x86_64

glib2-devel is needed by rrdtool-1.4.7-1.el6.x86_64

gettext-devel is needed by rrdtool-1.4.7-1.el6.x86_64

intltool is needed by rrdtool-1.4.7-1.el6.x86_64

libpng-devel is needed by rrdtool-1.4.7-1.el6.x86_64

libxml2-devel is needed by rrdtool-1.4.7-1.el6.x86_64

lua-devel is needed by rrdtool-1.4.7-1.el6.x86_64

openssl-devel is needed by rrdtool-1.4.7-1.el6.x86_64

pango-devel is needed by rrdtool-1.4.7-1.el6.x86_64

python-devel >= 2.3 is needed by rrdtool-1.4.7-1.el6.x86_64

ruby is needed by rrdtool-1.4.7-1.el6.x86_64

ruby-devel is needed by rrdtool-1.4.7-1.el6.x86_64

tcl-devel is needed by rrdtool-1.4.7-1.el6.x86_64

tk-devel is needed by rrdtool-1.4.7-1.el6.x86_64

xulrunner-devel is needed by rrdtool-1.4.7-1.el6.x86_64

zlib-devel is needed by rrdtool-1.4.7-1.el6.x86_64

因为是在powerlinux上安装

rpmbuild --rebuild rrdtool-1.4.7-1.rf.src.rpm

yum install perl-rrdtool-1.4.7-1.el6.x86_64.rpm rrdtool-1.4.7-1.el6.x86_64.rpm

三、配置

rrdcached基本思想就是在内存中合并更新，批量写磁盘，可以减轻写入磁盘的io负载，同时gweb也可以直接利用rrdcached中的数据进行绘图，也能减轻gweb绘图时请求的io负载，所以配置时建议gmetad和gweb都配置

rrd

[root@mast1 ~]# cat /etc/sysconfig/rrdcached

RUN_RRDCACHED=1

RRDCACHED_USER="rrdcached"

OPTS="-l /var/lib/ganglia/rrds -w 300 -z 300"

PIDFILE="/var/run/rrdcached/rrdcached.pid"

SOCKFILE="/var/run/rrdcached/rrdcached.sock"

SOCKPERMS=0660

安装包不同有可能默认的rrdcached配置文件也不同，如下也可参考

[root@cdh1 conf.d]# cat /etc/sysconfig/rrdcached

# Settings for rrdcached

#OPTIONS="-l unix:/var/rrdtool/rrdcached/rrdcached.sock -s rrdcached -m 664 -b /var/rrdtool/rrdcached"

OPTIONS="-l /var/rrdtool/rrdcached/rrdcached.sock -p /var/rrdtool/rrdcached/rrdcached.pid  -s rrdcached -m 664 -b /var/lib/ganglia/rrds"

RRDC_USER=rrdcached

gmetad

[root@mast1 ~]# grep -i rrdcached /etc/init.d/gmetad

export RRDCACHED_ADDRESS=/var/run/rrdcached/rrdcached.sock

gweb

[root@mast1 ~]# grep -i rrdcached /usr/share/ganglia/conf_default.php

$conf['rrdcached_socket'] = "/var/run/rrdcached/rrdcached.sock";

四、启动

gmond-》rrdcached-》gmetad-》gweb