While trying to setup ELK(Elastic Search, Logstash and Kibana) I got an error saying “Connection Failed”
If you are suing elastic search version 1.4 or above this issue will occur.
To resolve it append following lines in elasticsearch.yml file(which is in config directory of elastic search):
After adding above lines restart elasticsearch.
This should fix “Connection Failed” issue.
By using rrdtool tune we can remove negative spikes from any rrd(round robin database).
$ rrdtool tune --minimum ds-name:min
where, ds-name is the name you will use to reference this particular data source from an RRD.
min is minimum value, if we set minimum value of zero, it prevents negative rates.
In this example I am using test.rrd as my input rrd file.
To get ds-name first extract rrd file and with following command:
Suppose you come across the following command in a script. You are not quite sure what it does. Specifically, you want to know the meaning of each command argument.
$ wget --spider -r -nd -nv -H -l 1 -w 2 -o test.log http://example.com/ Traditionally, to find out what each argument does, you look up the
man page for the
wget command. Then, you scroll through page after page of information, and extract the description for each argument. This is a time-consuming, and eye-straining exercise.
The glob module finds all the pathnames matching a specific pattern according to the rules used by the Unix Shell. No tilde expansion is done, but *, ?, and character ranges expressed with  will be correctly matched.
To list all files ending with *.txt in /home/guest directory:
>>> import glob
[‘/home/guest/syslog.txt’, ‘/home/guest/mysql.txt’, ‘/home/guest/topics.txt’, ‘/home/guest/bus.txt’]
Dropbox gives you up to 16GB free. Google Drive & Gmail give you 15GB.OneDrive gives you 15GB.Box gives you 10GB.
Due to the Ghost bug aka CVE-2015-0235, we had to upgrade 500+ system vm’s. We’re running CloudStack 4.4.2. The version of the systemvm template it uses was 4.4.1 and so we created 4.4.2 and used that instead. It was quite some work to get it done so we thought it was worth sharing how we […]
To download a url with basic authentication we need to pass username & password.
To acheive this functionality with wget or curl observer following examples:
$ curl -u 'username:password' 'http://www.example.com'
$ wget --user='username' --password='password' 'http://www.example.com'
Wget with cookie:
By using slicing technique we can remove first ans last character from a string.
Observe following example for more details:
>>> input = "abcd"
In above example I removed a and d from input string (‘abcd’) with input[1:-1], so out our output is ‘bc’.