Skip to main content

Munin CPU Disk Throughput reduction load average

The System

I run Munin 2.0.16 on CentOS 6 to monitor about 30 hosts.
I mostly monitor 25-30 parameters per host (this depends to the running services)
About half of the hosts are nearby (with a LAN latency) the other part is far (with about 250ms network latency).

The facts

I have noticed "munin-graph" and "munin-html" took a long time. Long enough to overlap themselves if I keep the interval default (5 minutes).
I also noticed a huge "load average"
One of the most annoying thing is the Munin cronjob exiting with error (leading to a mail sent to the administrators) because a lock file (the one of the previous launch) still existing. This is very noise generator and lead to lower the importance of messages sent by munin...

Some solutions

And I decided to put both /var/lib/munin and /var/www/html/munin in tmpfs.
In order to reduce the data loss when rebooting, I make an hourly dump to the disk file system. This is not expensive.

Results

I made it step by step: 
  1. /var/www/html/munin then watch a moment
  2. /var/lib/munin and see
About disk usage, this is what happened:
About load average, this is what happened:

Conclusion

I just saved some disk I/O mostly writes. Nothing more.

Popular posts from this blog

npm run build base-href

Using NPM to specify base-href When building an Angular application, people usually use "ng" and pass arguments to that invocation. Typically, when wanting to hard code "base-href" in "index.html", one will issue: ng build --base-href='https://ngx.rktmb.org/foo' I used to build my angular apps through Bamboo or Jenkins and they have a "npm" plugin. I got the habit to build the application with "npm run build" before deploying it. But the development team once asked me to set the "--base-href='https://ngx.rktmb.org/foo'" parameter. npm run build --base-href='https://ngx.rktmb.org/foo did not set the base href in indext.html After looking for a while, I found https://github.com/angular/angular-cli/issues/13560 where it says: You need to use −− to pass arguments to npm scripts. This did the job! The command to issue is then: npm run build -- --base-href='https://ngx.rktmb.org/foo&

Jenkins invalid privatekey

Publish over SSH, Message "invalid privatekey:" With quite recent (June-July 2020) installations of Jenkins and OpenSSH, I have the following error message when using the "Deploy overs SSH" Jenkins plug-in and publishing artifacts to the target overs SSH: jenkins.plugins.publish_over.BapPublisherException: Failed to add SSH key. Message [invalid privatekey: [B@d8d395a] This problem seems to be referenced here: https://issues.jenkins-ci.org/browse/JENKINS-57495 Just regenerate a key with the right parameters To solve it: ssh-keygen -t rsa -b 4096 Or ssh-keygen -t rsa -b 4096 -m PEM

Emacs TypeScript Development

Emacs Configuration for Typescript In order to comfortably develop on Node, React or Angular projects with Emacs, TIDE is a good solution. We have TypeScript code highlight (that is the minimum!) and code completion based on the codebase (not only on locally defined and builtins) In order to achieve that: Install Emacs (24+) Install Node Install Typescript (which will provide "tsserver") Install TIDE and some usefull dependencies Configure Emacs to use all those Node is then installed in " /home/mihamina/Apps/node-v12.18.0-linux-x64/bin ": you should add it to your PATH. Installing Typescript is done with: npm install --save typescript @types/browserify After that, "tsserver" will be in " /home/mihamina/node_modules/.bin " Then comes the installation of TIDE: With the Emacs package manager, M-x package-install , install "tide". Do the same for "web-mode", "flycheck", "company" "js2-mode" and "