Thursday, April 12, 2012

Using Chainsaw to view Servicemix logs

Chainsaw is an open-source GUI-based log viewer. If you’ve ever wanted to utilize chainsaw to view Servicemix log file then this post is for you!
I use FuseSource distribution of Servicemix (aka Fuse ESB.
You can download Fuse ESB here:
I was able to visualize the Servicemix logs inside the Chainsaw GUI using the following steps:
1)      Install Chainsaw.
Download the latest distribution of chainsaw.
I downloaded the “Unix/Dos standalone version”
Extract to location of choice.
2)      Configure Chainsaw to listen for logging events on a given port.
Into the directory where I extracted chainsaw, I created a file “chainsaw-config.xml” with the following contents.
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration >
<log4j:configuration xmlns:log4j="" debug="true">
    <plugin name="SocketReceiver"
       <param name="Port" value="4445"/>
      <level value="debug"/>

The above configures chainsaw with a SocketReceiver that will listen on port 4445 to receive logging events.

3)      Configure Servicemix to send logging events.

Now to configure Servicemix to send logging event to this port you will update the Servicemix configuration. Edit the config file ‘org.ops4j.pax.logging.cfg’. Use the following as a guide for editing this file:

# the below line is an ‘edit’ of exising line – added a Chainsaw appender

log4j.rootLogger = INFO, sift, Chainsaw, osgi:VmLogAppender

# the below are completely new lines to configure the Chainsaw appender

log4j.appender.Chainsaw =

log4j.appender.Chainsaw.remoteHost = localhost

log4j.appender.Chainsaw.port = 4560

Make sure the “remoteHost” is the IP for the machine where you are running Chainsaw (or localhost) if you plan to run Chainsaw GUI on same box as Servicemix. Once you save this file the changes will take effect immediately, should be no need to restart Servicemix.
You may see Servicemix complain about not being able to find a receiver for its events. That’s because you don’t have Chainsaw up yet. Don’t worry Servicemix will retry again once you stand up the Chainsaw GUI.
4)      Bring up Chainsaw
From the directory where you installed chainsaw, run the file ‘chainsaw.bat’.
When you start first time it will give you a warning about not having Receivers defined. You can select “Let me use a simple Receiver:” and select “SocketReceiver” on port “4560 (Default SocketAppender port.)”
5)      View the logs in Chainsaw
Since we are experimenting, you may want to turn up the logs in Servicemix to prove all the logs are reaching Chainsaw.

From the Servicemix console type:
log:set DEBUG root

This will turn up the logging to highest level.

Once Servicemix sends an event. You will eventually see a tab pop up in Chainsaw that contains the logs it receives from the Servicemix instance. You should see quite a bit of logging being displayed in Chainsaw.

To turn off the excessive logging in Servicemix and return Servicmix to the default logging level, from the Servicemix console type:

log:set INFO root

I'm not totally convinced yet whether this will be a useful capability. I'm open to suggestions on how this might be used, or whether people are using this sort of thing at all. I'm a little disappointed in the overall model, that is Servicemix must be configured to send logs to Chainsaw.

1 comment:

  1. One follow up..

    The more i think about this model for how chainsaw receives logging events, the less i see usefulness for it.

    The model where servicemix connects to chainsaw and and sends data, seems backwards to me. You configure servicemix to point to an instance of chainsaw. That means for every chainsaw (remote listener), we have to configure another host/port in Servicemix to send events to that instance of chainsaw.

    I think a superior model would be from chainsaw, you configure chainsaw to connect to some logging server "hub" and receive LoggingEvents. Thats basically what SockerHubAppender does, it creates an effective logging server, letting you connect to it and receive. Now if we could get servicemix to create a SocketHubAppender and then and then configure chainsaw to connect to Servicemix (to begin receiving logging events) - that would be a model i could live with! Or even if we had a single "hub" instance of chainsaw (aka logging server) and remote chainsaw instances could connect to the hub.

    Seems like this was also part of the thinking in whats referred to here:

    and implemented in chainsaw here.

    all this is apparently experimental stuff though.

    If anyone has experience in this area, would love to here!