jonny » Red Branch

Querying Zookeeper from Python

November 6, 2018 jonny python

Install the prerequisites. Below works for Debian-based distros such as Ubuntu/Mint:

apt-get install libzookeeper-mt-dev

1	apt-get install libzookeeper-mt-dev

Install python libraries:

pip install zkpython pykeeper

1	pip install zkpython pykeeper

Example code below shows making a connection, getting the names of some child nodes and pulling info from each of those child nodes:

import pykeeper
import json

client = pykeeper.ZooKeeper('192.168.1.2:2181')
client.connect()

coords = client.get_children('/druid/coordinator/_COORDINATOR')

list_of_coord_addresses = []

for coord in coords:
  zk_coord = client.get('/druid/coordinator/_COORDINATOR/%s' % coord )
  list_of_coord_addresses.append(zk_coord[0])

print(list_of_coord_addresses)

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import pykeeper

import json

client = pykeeper.ZooKeeper('192.168.1.2:2181')

client.connect()

coords = client.get_children('/druid/coordinator/_COORDINATOR')

list_of_coord_addresses = []

for coord in coords:

zk_coord = client.get('/druid/coordinator/_COORDINATOR/%s' % coord )

list_of_coord_addresses.append(zk_coord[0])

print(list_of_coord_addresses)

Unfortunately I can’t get this installed on CentOS.

Install check_mk on Ubuntu 18.04

November 5, 2018 jonny nagios

Ubuntu 18.04 includes check-mk in the repository version but it is an older version 1.2.8 (at the time of writing). Download check mk raw (get the latest stable URL from the website) :

wget https://mathias-kettner.de/support/1.5.0p7/check-mk-raw-1.5.0p7_0.bionic_amd64.deb

1	wget https://mathias-kettner.de/support/1.5.0p7/check-mk-raw-1.5.0p7_0.bionic_amd64.deb

Try installing it:

dpkg -i dpkg -i check-mk-raw-*.deb

1	dpkg -i dpkg -i check-mk-raw-*.deb

You may get dependency issues which can be resolved with:

apt-get install -f

1	apt-get install -f

Then try the install again:

dpkg -i check-mk-raw-*.deb

1	dpkg -i check-mk-raw-*.deb

iDRAC 9 Set Physical Disk to Non-RAID

October 30, 2018 jonny Uncategorized

In the update from iDRAC 8 to iDRAC 9 it has been infuriating searching the ‘Storage’ menu only to discover that the storage is managed under ‘Configuration > Storage Configuration’ I’m convinced the user experience could be better! At the very least a link through for configuration.

Clearing old Journald Logs

October 1, 2018 jonny Uncategorized

Journald logs can be cleared by timescale or size as follows. Keep only 5 days worth of logs journalctl –vacuum-time=5d Retain only the past 500 MB: journalctl –vacuum-size=500M

Checking if Puppet is Disabled

October 1, 2018 jonny puppet

The puppet agent can be disabled from running with:

puppet disable "Some message here"

1	puppet disable "Some message here"

And it can be re-enabled with:

puppet enable

1	puppet enable

But to check if puppet is currently disabled there is no check command. Instead look for the existence of the agent_disabled.lock file under:

$vardir/state/agent_disabled.lock

1	$vardir/state/agent_disabled.lock

For the systems I was checking this was at:

/opt/puppetlabs/puppet/cache/state/agent_disabled.lock

1	/opt/puppetlabs/puppet/cache/state/agent_disabled.lock

Exclude Directories for Disk Usage (du)

August 29, 2018 jonny linux, shell

I sometimes want to omit directories from my disk usage (du -sh *) checks. This includes virtual files systems such as proc / dev and also mounts to other filesystems (data in the example below). This is what works for me:

du --exclude={proc,sys,dev,data} -sh *

1	du --exclude={proc,sys,dev,data} -sh *

The equals sign appears to be optional and worked both ways for me…. Read more »

Joining Multi-line Output with Paste

July 31, 2018 jonny shell

I was checking the memory on approximately 140 servers using ansible:

ansible --user root -k -i servers.list -m shell -a  "free -h; mysql" test

1	ansible --user root -k -i servers.list -m shell -a "free -h; mysql" test

but the output appears over several lines e.g.

server103.domain.dev | SUCCESS | rc=0 &gt;&gt;
total used free shared buffers cached
Mem: 94G 44G 49G 59M 203M 4.6G
-/+ buffers/cache: 39G 54G
Swap: 0B 0B 0B

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server103.domain.dev | SUCCESS | rc=0 >>

total used free shared buffers cached

Mem: 94G 44G 49G 59M 203M 4.6G

-/+ buffers/cache: 39G 54G

Swap: 0B 0B 0B

but what I wanted was the server name and the total memory available. So I first grepped the output to remove the lines I didn’t want e.g.

grep -A3 "domain.dev" | egrep -v "^--|Swap|total|buffer"

1	grep -A3 "domain.dev" \| egrep -v "^--\|Swap\|total\|buffer"

leaving me with two lines of… Read more »

Datanode denied communication with namenode

June 29, 2018 jonny hadoop

In a Cloudera cluster we had a few nodes reporting the following error message in the logs under hadoop-cmf-hdfs-DATANODE-whatever.com.log.out The error included: Datanode denied communication with namenode because the host is not in the include-list: : DatanodeRegistration One solution could be to ‘Refresh Node List’ as shown in the screenshot below. Find it by clicking… Read more »

Set NTP Server on Windows Domain Controller

June 5, 2018 jonny wordpress

On the Windows Domain Controller I checked the current NTP settings with:

w32tm /query /configuration

1	w32tm /query /configuration

I tried a few alternative commands and got errors such as “the rpc server is unavailable”. The command that worked was:

w32tm /config /manualpeerlist:time.windows.com /syncfromflags:manual /reliable:yes /update

1	w32tm /config /manualpeerlist:time.windows.com /syncfromflags:manual /reliable:yes /update

After issuing that command I could see the ntp server listed when re-running the command:

w32tm /query /configuration

1	w32tm /query /configuration

As shown below.

Windows Nagios Checks using NSClient

May 29, 2018 jonny nagios

I wanted to add some checks to a Windows server and the methods seem to have changed a little over the years. At the moment I have amended the nsclient.ini file on the Windows box with:

CheckDisk=1
CheckSystem=1

1 2	CheckDisk=1 CheckSystem=1

Then from the Nagios box I can check CPU with a threshold as follows:

/usr/lib64/nagios/plugins/check_nrpe -H winserver001.domain.tld --command check_cpu -a "warn=load > 96" "crit=load > 99" "time=5m"

1	/usr/lib64/nagios/plugins/check_nrpe -H winserver001.domain.tld --command check_cpu -a "warn=load > 96" "crit=load > 99" "time=5m"

We can also… Read more »

Posts By: jonny