Monitor Docker Platform
Docker is an open platform for developing, shipping, and running applications. Docker provides the ability to package and run an application in a loosely isolated environment called a container. The container becomes the unit for distributing and testing your application.
Docker running on linux can be monitored using Snappyflow sfagent. Refer the link for installation of sfagent.
Add the following configuration to the config.yaml file:
key: <profile key>
Name: <unique instance name or will be generated from IP>
appName: <add application name>
projectName: <add project name>
- name: docker
|systemUsage||Total System time consumed||Seconds|
|totalUsage||Total CPU time consumed||Seconds|
|usagePercent||CPU Usage in percentage||Percent|
|usageInKernelMode||Time spent by tasks of the cgroup in kernel mode||Seconds|
|usageinUserMode||Time spent by tasks of the cgroup in user mode||Seconds|
|throttledPeriods||Number of periods when the container hits its throttling limit||Count|
|periods||Number of periods with throttling active||Count|
|throttledTime||Aggregate time the container was throttled for in seconds||Seconds|
|systemTime||The CPU system time metric represents the percentage of time that CPU is executing system calls on behalf of processes.||Seconds|
Block IO Statistics
|ioServicedRecursiveSync||Count of sync performed||Regardless of size|
|ioServicedRecursiveAsync||Count of async performed||Regardless of size|
|ioServicedRecursiveRead||Count of read performed||Regardless of size|
|ioServicedRecursiveWrite||Count of write performed||Regardless of size|
|ioServiceBytesRecursiveSync||Count of sync performed||Bytes|
|ioServiceBytesRecursiveAsync||Count of sync performed||Bytes|
|ioServiceBytesRecursiveRead||Count of sync performed||Bytes|
|rxPackets||Network packet count received||Count|
|txPackets||Network packet count sent||count|
|rxErrors||Packets received with errors||Error|
|txError||Errors in packet transmission||Error|
|rxBytes||Network traffic volume received||Bytes|
|txBytes||Network traffic volume sent||Bytes|
|rxDropped||Packets dropped received||Error|
|txDropped||Packets dropped sent||Error|
|tasksDesired||No of task desired||Count|
|serviceName||Swarm service service Name||String|
|serviceMode||Swarm service service Mode||String|
|Serviced||Swarm service service Id||String|
|tasksRunning||No of task Running||Count|
|cache||Cache memory reflects data stored on disk that is currently cached||Bytes|
|totalCache||Total cache memory reflects data stored on disk that is currently cached||Bytes|
|activeAnon||RSS itself can be further decomposed into active||Bytes|
|totalActiveAnon||Total active anon||Bytes|
|inactiveAnon||RSS itself can be further decomposed into inactive||Bytes|
|totalInactiveFile||Total inactive anon||Bytes|
|activeFile||Cache can be further decomposed into active file||Bytes|
|totalActiveFile||Total active file||Bytes|
|inactiveFile||Cache can be further decomposed into inactivefile||Bytes|
|totalInactiveFile||Total Inactive file||Bytes|
|unevictable||Unreclaimable memory consumed by userspace||Bytes|
|totalUnevictable||Total unreclaimable memory consumed by userspace||Bytes|
|totalPgpgout||Total page out||Bytes|
|totalPgfault||Total segmentation fault||Bytes|
|totalPgmajFault||Fetching data from disk instead of memory||Bytes|
|writeback||Memory usage of a container for write back||Bytes|
|mappedFile||No of mapped files||Bytes|
|totalMappedFile||Total no of mapped files||Bytes|
|hierarchicalMemswLimit||Hierarchical Memory sw Limit||Bytes|
|hierarchicalMemoryLimit||Hierarchical Memory Limit||Bytes|
|totalWriteback||Total no of writeback||Bytes|
|rss||Non-cache memory for a process||Bytes|
|totalRss||Total Non-cache memory for a process||Bytes|
|rssHuge||Resident set size huge||Bytes|
|totalRssHuge||Total resident set size huge||Bytes|
Health status of docker is displayed as "unknown" if no healthcheck is added to the Docker file.
Enabling swarm will display the swarm statistics on the dashboard, else an empty box is displayed.
Follow the steps below to know how to enable:
- Add health check
- Add swarm to the docker container
A HEATHCHECK instruction determines the state of a Docker Container. It determines whether the Container is running in a normal state or not. It performs health checks at regular intervals. The initial state is starting and after a successful checkup, the state becomes healthy. If the test remains unsuccessful, it turns into an unhealthy state.
Some options provided by the HEALTHCHECK instruction are:
- --interval=: It determines the interval between 2 health check-ups. The default interval is the 30s.
- --timeout=: If the HEALTHCHECK command exceeds the specified duration, it is categorized as a failure. The default duration is the 30s.
- --retries=: If it reaches the specified number of retries, the state is unhealthy. The default number of retries is 3.
Add the health check instruction with options and a command or a blank health check in the Docker File , refer the given example.
HEALTHCHECK --interval=35s --timeout=4s CMD curl -f <protocol>://<IP>/ || exit 1
#Replace the protocol, IP and port as per requirements
#Ex: HEALTHCHECK --interval=35s --timeout=4s CMD curl -f https://localhost/ || exit 1
Re-build of docker is required after adding healthcheck in the docker file. Use the following command to build the docker.
Docker Swarm is an orchestration management tool that runs on Docker applications. It helps end-users in creating and deploying a cluster of Docker nodes. Each node of a Docker Swarm is a Docker daemon, and all Docker daemons interact using the Docker API. Docker Swarm can reschedule containers on node failures. Swarm node has a backup folder which we can use to restore the data onto a new Swarm.
There are two types of nodes in Docker Swarm:
- Manager node-Maintains cluster management tasks
- Worker node-Receives and executes tasks from the manager node
Steps to be followed to add swarm
Run the command
docker swarm init
Follow the instruction from the docker swarm init
docker swarm join –token “token”
docker swarm join -token manager
Docker swarm info details are shown only when a service is running.
To add services, run the following command
docker service create --name <service name> -p 80:80 httpd
Viewing data and dashboards
Data collected by plugins can be viewed in SnappyFlow’s browse data section
- Plugin =
docker, containerStatic, containerUtils, containerNetwork, dockerSwarm
- Dashboard template: