Archive for the ‘Linux’ Category

6 Useful Bash tips I wish I knew from day zero

Here’s a few bash commands tricks I wished I’d been shown when I first picked up the shell. Please share any additional favorites you have. Repeat the last command with sudo How often do you type… ?View Code BASHyum install long-list packages-devel Only to be told… You need to be root to perform this command. […]

Kibana splits on hostname

If you’re playing with Kibana and you notice any Pie charts splitting values incorrectly, i.e. on a hostname with hyphen characters, then here’s the fix you need to apply. It’s actually somethingĀ elasticsearch does… curl -XPUT http://localhost:9200/_template/syslog -d ‘ { “template”: “*syslog*”, “settings” : { “number_of_shards” : 1 }, “mappings” : { “file” : { “properties” […]

Bash script to execute a MariaDB query multiple times

This simple bash script will execute a query 100 times against a MySQL instance. It also uses the time command to report how long the entire process took. I use this for some very simple bench-marking. The query used here creates a temporary table and inserts 100K rows into it. You need the sequence engine […]

Copy date stamped backups with a regex & scp

Lets assume you have a directory of date stamped backups you want to scp to another location… backup_20141003.tar.gz backup_20141004.tar.gz backup_20141005.tar.gz backup_20141006.tar.gz backup_20141007.tar.gz backup_20141008.tar.gz backup_20141009.tar.gz scp can accept a regex like below to do this as a one-liner. Note the quotes are required for the expression to work. ?View Code BASHscp "user@hostname:/data/backup/backup_2014100[3-9].tar.gz" /path/to/location/ You should see […]

Modifying elasticsearch index settings

To view the settings of an index run the following at the command-line… ?View Code BASHcurl -XGET http://hostname:9200/indexname/_settings From here you can indeify the setting you need and modify it as you wish. This example sets the number of replicas to zero. ?View Code BASHcurl -XPUT http://hostname:9200/indexname/_settings -d ‘{ "index": {"number_of_replicas":"0"}}’ For further details see […]