Remoting Monitoring with OpenTelemetry - Coding Phase 1

[amurleopard]

Goal

The goal of this project:

• collect telemetry data(metrics, traces, logs) of remoting module with OpenTelemetry.

• send the telemetry data to OpenTelemetry Protocol endpoint

Which OpenTelemetry endpoint to use and how to visualize the data are up to users.

OpenTelemetry

An observability framework for cloud-native software

OpenTelemetry is a collection of tools, APIs, and SDKs. You can use it to instrument, generate, collect, and export telemetry data(metrics, logs, and traces) for analysis in order to understand your software’s performance and behavior.

Phase 1 summary

User survey

Our team conducted a user survey to understand the pain point regarding Jenkins remoting.

Fig 1. What agent type/plugins do you use?

Fig 1 shows what types of agent users use, and 17 unique respondents out of 28 use docker for agent. So I’m planning to publish a docker image to demonstrate how we can build Docker image with our monitoring feature.

This survey and investigation of JIRA tickets of past two years also tell me five common causes of agent unavailability.

• Configuration mistakes

  • Jenkins agent settings, e.g. misuse of "tunnel connection through" option.

  • Platform settings, e.g. invalid port setting of Kubernetes' helm template.

  • Network settings, e.g. Load balancer misconfiguration.

• Uncontrolled shutdown of nodes for downscaling.

• Timeout during provisioning a new node.

• Firewall, antivirus software or other network component kill the connection

• Lack of hardware resources, e.g. memory, temp space, etc…​

We also heard valuable user voice in the survey.

What areas would you like to see better in Jenkins monitoring?

I have created a bunch of adhoc monitoring jobs to check on the agent’s health and send e-mail. Would be nice to have this consolidated.

Having archive of nodes with the access to their logs/events would have been nice.

I hope that implementing these feature with OpenTelemetry, which is expected to become the industry standard for observability, will bring great monitoring experience to Jenkins community.

Proof of Concept

How to deliver the monitoring program to agents

1. Sending monitoring program to the agent over remoting

In my first implementation, I prepared a Jenkins plugin and send the monitoring program from Jenkins controller. However, this approach have following disadvantages.

1. We cannot collect telemetry data before the initial connection. We are likely to encounter a problem while provisioning a new node, so it’s important to observe agents' telemetry data from the beginning.

2. Some agent restarters (e.g. UnixSlaveRestarter) restart agent completely when reconnecting. It means that the agent lost monitoring program every time the connection closed, and we cannot collect telemetry data after the connection is lost before a new connection is established.

So we decided to take the next approach.

2. Install monitoring engine when provisioning a new agent

In this approach, user will download the monitoring program called monitoring engine, which is a JAR file, and place it in the agent node when provisioning.

How to instrument remoting to produce remoting trace

Add instrumentation extension point to remoting

Pull Request: https://github.com/jenkinsci/remoting/pull/471

This approach makes the agent launch command more complicated, and we have to overcome this problem.

Current State

Metrics

We currently support the following metrics and planning to support more.

Traces

We tried several approaches to instrument remoting module, but good approach is not established yet.

Here is a draft documentation of the spans to collect. Google Doc

Logs

Coming soon!

Metric and span demo visualization

Our team created a demo example with Docker compose and visualized the metrics and spans.

Click to open in new tab

Google Summer of Code Midterm Demo

Our project demo starts with 8:20

Next Step

• Log support

• Alpha release!

metrics	unit	label	key	description
system.cpu.load	1			System CPU load. See com.sun.management.OperatingSystemMXBean.getSystemCpuLoad
system.cpu.load.average.1m				System CPU load average 1 minute See java.lang.management.OperatingSystemMXBean.getSystemLoadAverage
system.memory.usage	bytes	state	used, free	see com.sun.management.OperatingSystemMXBean.getTotalPhysicalMemorySize and com.sun.management.OperatingSystemMXBean.getFreePhysicalMemorySize
system.memory.utilization	1			System memory utilization, see com.sun.management.OperatingSystemMXBean.getTotalPhysicalMemorySize and com.sun.management.OperatingSystemMXBean.getFreePhysicalMemorySize. Report 0% if no physical memory is discovered by the JVM.
system.paging.usage	bytes	state	used, free	see com.sun.management.OperatingSystemMXBean.getFreeSwapSpaceSize and com.sun.management.OperatingSystemMXBean.getTotalSwapSpaceSize.
system.paging.utilization	1			see com.sun.management.OperatingSystemMXBean.getFreeSwapSpaceSize and com.sun.management.OperatingSystemMXBean.getTotalSwapSpaceSize. Report 0% if no swap memory is discovered by the JVM.
process.cpu.load	%			Process CPU load. See com.sun.management.OperatingSystemMXBean.getProcessCpuLoad.
process.cpu.time	ns			Process CPU time. See com.sun.management.OperatingSystemMXBean.getProcessCpuTime.
runtime.jvm.memory.area	bytes	type	used, committed, max	see MemoryUsage
		area	heap, non_heap
runtime.jvm.memory.pool	bytes	type	used, committed, max	see MemoryUsage
		pool	PS Eden Space, G1 Old Gen…​
runtime.jvm.gc.time	ms	gc	G1 Young Generation, G1 Old Generation, …​	see GarbageCollectorMXBean
runtime.jvm.gc.count	1	gc	G1 Young Generation, G1 Old Generation, …​	see GarbageCollectorMXBean

http://feedproxy.google.com/~r/ContinuousBlog/~3/mvm96V9yiTs/