4.2. Starting and stopping Trisul

The startup process involves.

start the domain — The control plane for Trisul probes and hubs
start the context — Probes and hubs
start the webserver — The user interface

Example to start all processes

The following example shows how to get the default Trisul context up and running from scratch.



# start the domain processes on hub
trisulctl_hub start domain

# start the domain processes on each probe
trisulctl_probe start domain

# start actual Trisul processes 
trisulctl_hub start context default

# start web server
systemctl start webtrisuld

The following sections go a bit deeper into each startup process.

4.2.1 Start and stop the domain process

Each probe and hub node needs a domain process to be up and running. This enables the node to communicate with the other nodes in the domain. This is done automatically only once at system startup time.

CLI tools trisulctl_hub and trisulctl_probe
Domain tasks cannot be performed by the Web Interface. Use the CLI app trisulctl_probe on the probes and trisulctl_hub on the hubs.

Starting the domain processes on the hub node

The domain processes on the hub node control the following functionalities

router – a node that routes messages (we use 0MQ )
hub – the DB and query node
config – holds the configuration parameters

To start the domain



trisulctl_hub start domain

or use the interactive CLI mode


ubuntu@ip-172-31-15-106:~$ sudo trisulctl_hub
Connecting to domain0 
Trisul Network Analytics version 6.0.2697
Hub Node Management tool
   * found  trisul-hub    /usr/local/etc/trisul-hub/domain0/domain.xml
   * connecting to domain0 at ipc:///usr/local/var/lib/trisul-hub/domain0/run/ctl_local_req
trisul_hub(domain0)> start domain
   * trisul_cp_hub        started with new pid=4117     public-key=/usr/local/etc/trisul-hub/domain0/hub0.cert
   * trisul_cp_config     started with new pid=4129     public-key=/usr/local/etc/trisul-hub/domain0/config0.cert
   * trisul_cp_router     started with new pid=4141     public-key=/usr/local/etc/trisul-hub/domain0/router0.cert

From the output you can see the domain processes trisul_cp_hub, trisul_cp_config, and trisul_cp_router are being started.
If you run start domain on a domain that is already running it will be safely ignored.
To stop the domain use stop domain.
Use list nodes command to see the status of the domain.

Starting the domain on the probe node(s)

Now you need to start the domain on each probe node. By default you only have one probe called probe0.

The domain processes on the probe node control the following nodes

probe – the trisul probe

To start the domain



trisulctl_probe start domain

Stop the domain

You typically do not have to stop the domain process on each node. You only need to do this if you are updating the certificates for the nodes or when you want a clean shutdown.

To stop the domain , log on to each probe node and enter


trisulctl_probe stop domain

and then log on to each hub node and enter


trisulctl_hub  stop domain

4.2.2 Start and stop contexts

A context is an independent instance of Trisul. Initially you only have a single context named default you may create additional contexts to create a multi-tenant setup. You can start/stop contexts on each probe or hub independently.

View contexts

To view all contexts and their running states use the info context command on trisulctl_hub or trisulctl_probe tool.

To view all contexts



trisulctl_hub

info context

To view specific context



trisulctl_hub (or trisulctl_probe)

info context default

Start context using CLI

To start a context from a CLI


trisulctl_hub start context default

the output could be something like



trisul_hub(domain0)> start context default

   + config0              started success.default

   + hub0                 started Successfully started context processes default@hub0

   + probe0               started Successfully started context processes default@probe0

Log from default@hub0 context default

Log from default@probe0 context default

trisul_hub(domain0)>

You can see that the context processes are automatically started on all domain nodes, even if they are on different physical machines.

To start a context only on a particular node – say probeEAST


start context default@probeEAST

Similarly you can use the stop context command.

Start context using Web UI

You can also do the same thing from the Web UI.

Login as admin
On the left menu – select the context you wish to work with. If you want to work with the default context – select Context: default
Select Start/Stop Tasks

You can then just click on the Start and Stop buttons against the hub and probe nodes.

Stop context using CLI

To stop a context from a CLI use the stop context command.

If you stop a hub context and if the probes are still running, you may experience some gaps in your data.

You can run this command from either the trisulctl_probe or trisulctl_hub tool, it will be executed on all domain nodes.

To stop context default



trisulctl_hub stop context default

To stop context default only on probeEAST



trisulctl_hub 

stop context default@probeEAST

You can also use stop context all to stop/start all contexts

4.2.3 Start and stop webtrisul

The web interface can simply be managed by the usual systemctl tool.

The service names for the webinterface are

webtrisuld – for normal HTTP based access
webtrisulssld – for HTTPS (SSL) access

Starting webtrisul


sudo systemctl start webtrisuld

Stopping webtrisul


sudo systemctl stop webtrisuld

To check errors with systemctl use journalctl -u webtrisuld

Starting webtrisul SSL server

The service name for the SSL webserver is webtrisulssld

See : How to switch to SSL Web Server


sudo systemctl start webtrisulssld

4.2.4 Automatically starting on boot

Trisul startup scripts make it easy to automatically start the system on every boot.

By default the following services automatically restart

webtrisuld.service | webtrisul
trisul-hub.service and trisul-probe.service | the domain processes

The following service is NOT automatically started

trisul-probe0-context0.service | the probe server

To start the Trisul probe as well , do the following


sudo systemctl enable 	trisul-probe0-context0

Starting the SSL server instead of the HTTP server

To start the SSL web server, you have to disable the HTTP service. See below.
If you enable both , neither of them may start properly.



sudo systemctl disable 	webtrisuld

sudo systemctl enable 	webtrisulssld