Categories
kafka

Check Kafka JMX node stats using JConsole

Hi,

As you probably know, Kafka is already publishing a lot of performance data on JMX to be collected.
In order to do this, you will need to install jconsole (for Windows it’s already embedded in the jdk installation, for Linux you can use this article to check it out https://www.garron.me/en/linux/find-which-package-library-belongs.html. After you have done that, you will have just to export the JMX_PORT variable to you env (for example export JMX_PORT=9999) before you start the Kafka node. When you will open JConsole you will probably see something like

After you select the Kafka node, it will tell you that the connection is not secure, but it doesn’t matter for my point of view and after that you can have a overview of the process. The statistics are available MBens tab and extra info regarding the meaning you can find in the official doku and also in the DataDog article.

This is a single simple node configuration, if it is required i will post some complex configurations, but this is required in special cases, standard monitoring using DataDog/Prometheus or other solution needs to be implemented in case of a bigger infrastructure.

Cheers

Categories
cloud newtools

Small Vagrant config file for Rancher deploy

Hi,

Just wanted to post this also, if it’s not that nice the config using a jumpserver, surely we can convert that to code (Puppet/Ansible), you can also use Vagrant. The main issue that i faced when i tried to create my setup is that for a reason (not really sure why, Vagrant on Windows runs very slow). However, i chose to give you one piece of Vagrantfile for a minimal setup on which you can grab the Rancher server framework and also the client containers.

Here is it:

# -*- mode: ruby -*-
# vi: set ft=ruby :
Vagrant.configure("2") do |config|
config.vm.define "master" do |master|
master.vm.box = "centos/7"
master.vm.hostname = 'master'
master.vm.network "public_network", bridge: "enp0s25"
end
config.vm.define "slave" do |slave|
slave.vm.box = "centos/7"
slave.vm.hostname = 'slave'
slave.vm.network "public_network", bridge: "enp0s25"
end
config.vm.define "swarmmaster" do |swarmmaster|
swarmmaster.vm.box = "centos/7"
swarmmaster.vm.hostname = 'swarmmaster'
swarmmaster.vm.network "public_network", bridge: "enp0s25"
end
config.vm.define "swarmslave" do |swarmclient|
swarmclient.vm.box = "centos/7"
swarmclient.vm.hostname = 'swarmclient'
swarmclient.vm.network "public_network", bridge: "enp0s25"
end
end

 

Do not worry about the naming of the machines, you can change them to whatever you like, the main catch is to bridge the public network in all of them in order to be able to communicate with each other and also have access to the docker hub. Beside that everything else that i posted regarding the registry to the Rancher framework is still valid.

Thank you for your time,

Cheers!

Categories
cloud kafka

Monitoring Kafka with DataDog

Hi,

A very interesting series of articles that should be checked regarding one option of Kafka monitoring with Datadog :

 https://www.datadoghq.com/blog/monitoring-kafka-performance-metrics/.

I will have in the near future a task regarding this, will post the outcome when it’s done.

P.S: It was done and you can find the implementation here :

Integrate Kafka with Datadog monitoring using puppet

As for the metrics point of view we will see if this is really an option, i have tried the same with Prometheus and Grafana and it seems to wok better. Keep you posted

Cheers

Categories
docker

Monitoring Kafka node using Docker

Hi,

Today i am just going to point you to a very interesting article related to monitoring of Kafka node/nodes using InfluxDB, Grafana and Docker. Hope it is useful, i will surely try it in one of the days.

https://softwaremill.com/monitoring-apache-kafka-with-influxdb-grafana/

Now this is not quite standard but nevertheless it is an option.

Cheers!

Categories
linux

Memory check by process in Linux

Hi,

I wanted to post this since it might be useful in some situations. On a Linux machine it seems that one way to check the memory usage by top processes is with ps aux –sort -rss (This means that it’s order by Resistent Set Size)  Once executed it will return an output similar to this:

USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
sorin 3673 0.6 27.3 3626020 563964 pts/1 Sl+ 02:24 1:09 java -Xmx1G -Xms1G -server -XX:+UseG1GC -XX:MaxGCPauseMillis=20 -XX:InitiatingHeapOccupancyPercent=35 -XX:+Disa
sorin 1708 2.0 9.2 1835288 189692 ? Sl 02:11 3:56 /usr/bin/gnome-shell
sorin 1967 0.6 8.0 1642280 166160 ? Sl 02:12 1:11 firefox-esr
sorin 3413 0.1 3.7 2000252 77016 pts/0 Sl+ 02:21 0:19 java -Xmx512M -Xms512M -server -XX:+UseG1GC -XX:MaxGCPauseMillis=20 -XX:InitiatingHeapOccupancyPercent=35 -XX:+
root 576 0.5 2.6 263688 54172 tty7 Ssl+ 02:11 1:07 /usr/bin/Xorg :0 -novtswitch -background none -noreset -verbose 3 -auth /var/run/gdm3/auth-for-Debian-gdm-Bu1jB
sorin 1813 0.0 2.2 1175504 47196 ? Sl 02:11 0:00 /usr/lib/evolution/evolution-calendar-factory
root 486 0.1 1.2 377568 26584 ? Ssl 02:11 0:21 /usr/bin/dockerd -H fd://

If you want to get more detail of a PID status you can go to /proc/[pid]/status and you can find a lot of other informations. For example the top process on my Linux machine has the following header:

sorin@debian:/proc/3673$ cat status
Name: java
State: S (sleeping)
Tgid: 3673
Ngid: 0
Pid: 3673
PPid: 3660
TracerPid: 0
Uid: 1000 1000 1000 1000
Gid: 1000 1000 1000 1000
FDSize: 256
Groups: 24 25 29 30 44 46 108 111 116 1000
VmPeak: 3626024 kB
VmSize: 3626020 kB

As you can see, the RSS is the same as VmSize.

Cheers!

Categories
Uncategorized

Register RancherOs to the Rancher framework

Hi,

After we were able to login via ssh on our machines, it’s time to put them to use by subscribing them to a orchestrating framework. One free and pretty powerful framework of such kind is given by the same company. In order to use it you will need to have Docker installed, more info on this topic following the link

 https://docs.rancher.com/rancher/v1.5/en/installing-rancher/installing-server/

Until now i haven’t tried the option for a HA configuration, i will do that in the near future and post the findings but for now it should be enough if we deploy a standard container for the management.

Using the command from the documentation i have managed to grab the image and start the following container:

417930c9f375 rancher/server "/usr/bin/entry /u..." 2 weeks ago Up 6 minutes 3306/tcp, 0.0.0.0:8080->8080/tcp eloquent_goodall

We have also the possibility to check the image using the docker images  command and we will have the following result:

rancher/server latest 2751db6ea7ec 4 weeks ago 935 MB

Once the container is started, you can access the UI by going to the address http://127.0.0.1:8080 (please keep in mind that you have binded the ports to be forwarded and accessible from any IP range, that is what 0.0.0.0:8080->8080/tcp should mean, if you want to be accessible for a specific range or IP please change this on docker run command.

Ok, once the administration console has been loaded you can go to Infrastructure -> Hosts -> Add Host. Please do not use the default site address, it is relevant only for the local container, instead it can be replaced by  http://[jumpserver ip address]:8080This will be used in order to obtain the registration string for the agents. When pressing OK, you will be redirected to a window with the necessary steps to be done for registration, please keep it open.

After connecting via ssh to the Rancher machine, please make sure that you have access to the Docker hub repo. You can easily do that by running docker search rancher. If there is a timeout error, please take a look on configuring proxy for docker, in our case on private machines it can be done using the following lines in cloud-config.yml located under /var/lib/rancher/conf

rancher:
network:
http_proxy: http://[user]:[password]@[proxyip]:[proxyport]
https_proxy: http://[user]:[password]@[proxyip]:[proxyport]

These lines being added you will need to reload the docker daemon by using the command system-docker restart docker and it should work.

Now go to the UI page and copy the string at the last step in our Rancher server window, it will start downloading the necessary containers in order to link with the framework.

This being done some images will be downloaded and started to the machine and started:

[rancher@rancher conf]$ docker images | grep rancher
rancher/scheduler v0.7.5 e7ff16ba4444 2 weeks ago 241.9 MB
rancher/network-manager v0.5.3 0f224908d730 2 weeks ago 241.6 MB
rancher/metadata v0.8.11 19b37bb3e242 5 weeks ago 251.5 MB
rancher/agent v1.2.1 9cecf992679f 5 weeks ago 233.7 MB
rancher/scheduler v0.7.4 7a32d7571cad 5 weeks ago 241.9 MB
rancher/net v0.9.4 5ac4ae5d7fa4 5 weeks ago 264.3 MB
rancher/network-manager v0.4.8 45bdcd2b1944 6 weeks ago 241.6 MB
rancher/dns v0.14.1 4e37fc4150c2 6 weeks ago 239.8 MB
rancher/healthcheck v0.2.3 491349141109 10 weeks ago 383.3 MB
rancher/net holder bb516596ce5a 3 months ago 261.7 MB
[rancher@rancher conf]$ docker ps -a | grep rancher
a3fde18ebdbd rancher/scheduler:v0.7.5 "/.r/r /rancher-entry" 3 days ago Exited (0) 3 days ago r-scheduler-scheduler-1-37fd65ec
35c7bbc1cb42 rancher/network-manager:v0.5.3 "/rancher-entrypoint." 3 days ago Up 30 minutes r-network-services-network-manager-1-57e1bbbd
3a048010be3d rancher/scheduler:v0.7.4 "/.r/r /rancher-entry" 2 weeks ago Exited (0) 3 days ago r-scheduler-scheduler-1-de6ec66f
fad7d11141aa rancher/net:v0.9.4 "/rancher-entrypoint." 2 weeks ago Up 29 minutes r-ipsec-ipsec-router-1-af053a8c
b7ce7b4f8520 rancher/dns:v0.14.1 "/rancher-entrypoint." 2 weeks ago Up 30 minutes r-network-services-metadata-dns-1-438fbeaa
30e5cab4b4c6 rancher/metadata:v0.8.11 "/rancher-entrypoint." 2 weeks ago Up 30 minutes r-network-services-metadata-1-827c71e3
382ebf55c3c1 rancher/net:holder "/.r/r /rancher-entry" 2 weeks ago Up 30 minutes r-ipsec-ipsec-1-55aeea30
0223f1ffe986 rancher/healthcheck:v0.2.3 "/.r/r /rancher-entry" 2 weeks ago Up 30 minutes r-healthcheck-healthcheck-1-f00a6858
03652d781c9a rancher/net:v0.9.4 "/rancher-entrypoint." 2 weeks ago Up 30 minutes r-ipsec-ipsec-cni-driver-1-797e0060
1b6d1664c801 rancher/agent:v1.2.1 "/run.sh run" 2 weeks ago Up 31 minutes rancher-agent
c8b8e4ddf91c rancher/agent:v1.2.1 "/run.sh http://10.0." 2 weeks ago Exited (0) 2 weeks ago furious_bohr

And also the server will appear in the UI. In next posts we will try to deploy some services from the catalog.

Cheers

Categories
Uncategorized

Install RancherOS on VirtualBox and configure it for ssh access

Hi,

If you are not familiar with what is RancherOS you can learn more from this link: Rancher docu It’s basically a very small Linux distro that runs all the processes as Docker containers (including the system processes).

So, starting from here, we will need a RancherOS image which you can download from the following location: Rancher git. After doing that you will need a VirtualBox machine with minimum 1GB of RAM (the reason for this is that Rancher will run at first from the memory). The size of the root partition can be as big as you like, no extra video configurations are required since it will run in CLI mode.

You also need to know that an extra jump server (or a server that is accessible over ssh protocol) is required in order to successfully configure your single/multiple running instance of Rancher and that is for a simple reason. As far as i managed to test, no mount command is working of an external USB storage (please be aware that we are talking about an isolated environment)  and also copy/paste is not running by default without Virtualbox Guest Tools installed (unfortunately this is also not possible because we will not have a GUI and these kind of releases are not supported, i think this is also the case of CoreOs). Please make sure that the servers are reachable and have sshd installed and configured.

Since Rancher is available only with ssh key login, because of security reasons, you will need to add it before install to the cloud-config.yml

On the jump server you need to generate a rsa key with the ssh-keygen command and it will create in the .ssh directory the following pair of files (this is a list from my test machine) :

-rw-r–r– 1 sorin sorin 394 Mar 21 08:09 id_rsa.pub
-rw——- 1 sorin sorin 1675 Mar 21 08:09 id_rsa

The next step is to build the minimal cloud-config file in order to get access to the machine, and in that purpose we can run the command

echo -e “#cloud-confignssh_authorized_keys:n – $(cat id_rsa.pub)” > $HOME/cloud-config.yml

This will create the only file you need in order to install your “server”.

Ok, it’s time to start our Rancher machine, please make sure that you have the Rancher image mounted in order to boot it. After this process is done you will need to connect to the jump server in order to grab the file created above. Please do that with the following command:

After this is done, we can install it on the local drive. Since it’s more simple with a printscreen i will list another one 🙂

Ok, this being done, you will be propted to restart the machine but before that please make sure that you have unmounted the rancher image from the virtual drive otherwise it will boot from it and not from the actual install.

You are almost done, after restart you can access the server via ssh rancher@[rancher server ip] if you used the default id_rsa key from the .ssh directory, and if not, ssh -i [private key file location] rancher@[rancher server ip]

More articles to come on this topic,

Cheers!

Categories
Uncategorized

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