SD-MON -- SD Erlang Monitor

Revision history

Rev. A   - 04/02/2015 - First release for D5.4 delivery.
Rev. B01 - 10/02/2015 - Added Makefile and localhost IP configuration.
Rev. B02 - 12/02/2015 - Free installation directory.
Rev. B03 - 18/02/2015 - Basic run-time visualization of message counters.
Rev. B04 - 12/03/2015 - Dynamic handling improvement.
Rev. B   - 07/04/2015 - WEB online visualization for inter-group messages.

Introduction

SD-Mon is a tool aimed to monitor SD-Erlang systems.

This purpose is accomplished by means a "shadow" network of agents, mapped on the running system.
The network is deployed on the base of a configuration file describing the network architecture in terms of hosts, Erlang nodes, global group and s_group partitions. Tracing to be performed on monitored nodes is also specified within the configuration file.

An agent is started by a master SD-Mon node for each s_group and for each free node. Configured tracing is applied on every monitored node, and traces are stored in binary format in the agent file system.

The shadow network follows system changes so that agents are started and stopped at runtime according to the needs. Such changes are persistently stored so that the last configuration can be reproduced after a restart. Of course the shadow network can be always updated via the User Interface.

The number of exchanged inter-node messages can be displayed at run-time, a WEB interface is available to follow inter-group messages.

As soon as an agent is stopped the related tracing files are fetched across the network by the master and they are made available in a readable format in the master file system and statistics are generated.

Description

A detailed description can be found in document "SD-Mon Tool Description".

Installation

To compile the code you need rebar in your PATH.

Type the following commands:

git clone https://github.com/RefactoringTools/SD-Mon
cd SD-Mon
make
make web

How to run SD-Mon

In the following we call "base directory" (or BASEDIR) the directory where the tool is installed, for instance BASEDIR = /data/proj. SD-Mon is started by executing from the installation directory (BASEDIR/SD-Mon) the bash script:

bin/sdmon_start

configuration files are read and the shadow network is started. By executing:

bin/sdmon_stop

SD-Mon is stopped: all tracing is removed, agents are terminated and all tracing files are downloaded in the master fylesystem (traces dir).

Example 1: SD-ORBIT on single-host

Open a terminal and type (after replacing <BASEDIR> with the actual base directory):

export PATH=<BASEDIR>/SD-Mon/bin/:<BASEDIR>/SD-Mon/test/bin/:$PATH
cd <BASEDIR>/SD-Mon
cd test/config
rm test.config  # if it exists
ln -s test.config.orbit test.config
cd ../../
run_env
sdmon_start -v

Open a new terminal and type:

export PATH=<BASEDIR>/SD-Mon/bin/:<BASEDIR>/SD-Mon/test/bin/:$PATH
cd <BASEDIR>/SD-Mon
watch_internode
sdmon_web_start

The terminal started by the watch_internode command will show internode message counters updating at runtime, each entry in the form {{FromNode, ToNode}, SentMessages}.

To observe inter-group messages as they are sent, open a web browser and navigate to 'localhost:8080'.

Now attach to node1 erlang shell and start the Orbit test from there:

to_nodes node1
sdmon_test:run_orbit_on_five_nodes().

When Orbit run is completed go back on the first terminal and type:

application:stop(sdmon).
sdmon_web_stop

Find tracing and statistics in <BASEDIR>/SD-Mon/traces.

Example 2: SD-ORBIT on multi-host

Some prerequisites apply in the multi-host case:

• SD-Mon must be installed in the home directory of the local host and on all non-local hosts.
• User must be able to execute SSH commands on target non-local hosts without the needs to provide a password (use ssh-keygen if needed). This demo runs on myrtle.kent.ac.uk (129.12.3.176) and on dove.kent.ac.uk (129.12.3.211). The userid granted to access remote nodes via SSH without password must be defined in test.config file (‘uid’ tag).

Edit the file <BASEDIR>/SD-Mon/test/config/test.config.orbit_3h and replace the string "md504" with the proper userid (see above).

Now open a terminal and type:

export PATH=<BASEDIR>/SD-Mon/bin/:<BASEDIR>/SD-Mon/test/bin/:$PATH
cd <BASEDIR>/SD-Mon
cd test/config
rm test.config
ln -s test.config.orbit_3h test.config
cd ../../
run_env
sdmon_start -v

Open a new terminal and type:

export PATH=<BASEDIR>/SD-Mon/bin/:<BASEDIR>/SD-Mon/test/bin/:$PATH
cd <BASEDIR>/SD-Mon
watch_internode2
sdmon_web_start

This time message counters will be displayed on 2 terminals.

To observe inter-group messages as they are sent, open a web browser and navigate to 'localhost:8080'.

Now attach to node1 erlang shell and start the Orbit test from there:

to_nodes node1
sdmon_test:run_orbit_on_nine_nodes().

When Orbit run is completed go back on the first terminal and type:

application:stop(sdmon).
sdmon_web_stop

Find tracing and statistics in <BASEDIR>/SD-Mon/traces.