NOTE: This release has been deprecated and is not supported.

cf-logmon

This application performs a blacbox test for measuring message reliability when running the command cf logs. This is accomplished by writing groups of logs, measuring the time it took to produce the logs, and then counting the logs received in the log stream. This is one way to measure message reliability of the Loggregator system. The results of this test are displayed in a simple UI and available via JSON and the Firehose.

Setup

To get started you'll need to create a user that you would like to use within the app (we recommend creating a specific user for performing the test rather than using "real" credentials). You will also need to install the jdk if you are not setup for Java development.

1. Create a space auditor user. The application needs this user to read logs. Because its credentials will be stored in an environment variable in CF, these credentials should not belong to any real user. An example set of commands to create a user:

   ORG=my-org
   SPACE=my-space
   USERNAME=logmon-user@mycompany.com
   PASSWORD=fancy-password
   cf create-user <username> <password>
   cf set-space-role <username> <org> <space> SpaceAuditor

2. git clone https://github.com/cloudfoundry-incubator/cf-logmon
   cd cf-logmon
   bin/deploy.rb

Then visit https://cf-logmon.$CF_DOMAIN. You should start seeing data within 5 minutes.

We've found that statistics become more valuable after 24 hours (or after a typical business day).

Configuration

The following environment variables are used to configure test output and rates:

• LOGMON_SKIP_CERT_VERIFY - Whether to skip ssl validation when connecting to CF

• LOGMON_PRODUCTION_LOG_CYCLES - The number of logs to emit during each test

• LOGMON_PRODUCTION_LOG_DURATION_MILLIS - The amount of time in milliseconds during which the logs will be emitted.

• LOGMON_PRODUCTION_LOG_BYTE_SIZE - The byte size of the log message to emit.

It is also possible to configure various wait times:

• LOGMON_TIME_BETWEEN_TESTS_MILLIS - The amount of time to wait between each "test"
• LOGMON_CONSUMPTION_POST_PRODUCTION_WAIT_TIME_MILLIS - The amount of time to wait after production completes for all created logs to drain.
• LOGMON_PRODUCTION_INITIAL_DELAY_MILLIS - The amount of time to allow a log consumption connection to start before producing logs.

Important Do not scale this application beyond a single instance. Nothing is done to distinquish app instances when consuming logs.

Web UI

This application includes a simple user interface for understanding your loss rate over the last 24 hours. The chart shoes the specific performance over the last 24 hours. The anamoly journal shows events when your log reliability rates falls below 99% (warning) and 90% (alert). This is a general guide to help operators better understand how to configure metrics.

Firehose Metrics

This application works best whenbound to the metrics-forwarder service. This allows the following metrics to be emitted by the application.

• metrics_forwarder.gauge.logmon.logs_produced
• metrics_forwarder.gauge.logmon.logs_consumed

The metrics are tagged with the application GUID of the app that is pushed.

Background

Due to the challenges of distributed systems, and untracked srouces of loss in the Loggregator system setting Service Level Objectives for message reliability has been difficult using whitebox monitoring tools. The Loggregator team developed series of blackbox tests to monitor and mesaure message reliability. This was developed as a stand alone applications through a collaboration with Pivotal Labs in Denver.