[MB-47591] Incorrect cgroup resource detection (core/memory) when running in Container / K8S - Couchbase database

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Details

Type: Bug
Status: Resolved
Priority: Major
Resolution: Fixed
Affects Version/s: 7.0.0
Fix Version/s: Morpheus, 7.1.1
Component/s: ns_server
Labels:
- approved-for-7.1.1
- candidate-7.1.1

Triage:
Triaged
Is this a Regression?:
Yes

Description

We need to calculate the right number of cores configured by the container environment and ensure all services use it. Since NS-SERVER is the bootstrapping all services, we'll need to add logic to detect and pass on the proper args/env as appropriate to the type of runtime a service is using.

Most of our services uses a some flavor of managed virtual machine (Java, Golang, Erlang). These are the actual components that automatically detects number of cores, based on whichever calls they make to the OS. Some may offer a way to manually force number of cores avail to the virtual machine. Each service will need to provide bootstrapping guidance how to limit theirs. Then, we can add a wrapper to the bootstrapping that detects whether or not, cgroups is in use and calculate the cores made available to the container and pass it on to the startup script of each service and use the proper arguments to restrict the number of cores. Since most services are started by the babysitter, this can be done centrally by ns_server.

Java : command line -XX:ActiveProcessorCount=<cores>
Golang : environment variable GOMAXPROCS=<cores>
Erlang: command line +S <cores>:<cores>
C/C++: No Virtual Machine. cgroup detection logic needs to be prescribed in code.

Important to note, as the number of threads created by each service may, or may not be derived by the number of available cores, each service will need to adjust their logic of thread allocation. In the case of Erlang based processes (NS_SERVER, COUCHDB), there will be one thread per core by default. So adjusting number of cores will also impact number of threads.

Attachments

Issue Links

blocks

CMOS-233 Memory statistics in containers use those of the host

To Do

K8S-2724 Add tests for cgroup/COUCHBASE_CPU_COUNT changes

Open

depends on

MB-52029 Eventing Service should honor the CPU & Memory limits set in cgroups

Open

MB-52030 FTS should honor the CPU & Memory limits set in cgroups

Open

MB-51864 The Backup Service should honor the GOMAXPROCS env var if specified

Resolved

MB-40464 CPU statistics in containers limited via CFS are misleading

Closed

MB-49632 cb::get_available_cpu_count ignores CPU quota

Closed

MB-51866 [cbas] Respect COUCHBASE_CPU_COUNT env (set max num of threads for JVM)

Resolved

relates to

MB-50341 Support new cgroup API from sigar

In Progress

MB-48247 Account for container memory and cpu limits in plasma storage

Closed

MB-49381 Projector memory monitoring doesn't work correctly in memory limited containers

Closed

MB-40464 CPU statistics in containers limited via CFS are misleading

Closed

MB-48873 Consider runtime.GOMAXPROCS(0) vs runtime.NumCPU()

Closed

MB-48247 Account for container memory and cpu limits in plasma storage

Closed

MB-49382 [CBSE][sigar] Indexer CPU and memory monitoring doesn't work correctly in CPU limited containers

Closed

K8S-2514 [Self Cert Tool] Enhance PreFlight checks to get actual count of PID limit on containers.

Open

links to

Design Approach

PRD

(3 depends on, 8 relates to, 2 links to)

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View 34 older comments

Couchbase Build Team added a comment - 06/May/22 9:59 PM

Build couchbase-server-7.2.0-1120 contains ns_server commit 50984d6 with commit message:
~~MB-47591~~: Use cgroups data from sigar for stats

Couchbase Build Team added a comment - 06/May/22 9:59 PM Build couchbase-server-7.2.0-1120 contains ns_server commit 50984d6 with commit message: MB-47591 : Use cgroups data from sigar for stats

Couchbase Build Team added a comment - 06/May/22 9:59 PM

Build couchbase-server-7.2.0-1120 contains ns_server commit 4878689 with commit message:
~~MB-47591~~: [sigar] Take care of paddings when...

Couchbase Build Team added a comment - 06/May/22 9:59 PM Build couchbase-server-7.2.0-1120 contains ns_server commit 4878689 with commit message: MB-47591 : [sigar] Take care of paddings when...

Couchbase Build Team added a comment - 06/May/22 9:59 PM

Build couchbase-server-7.2.0-1120 contains ns_server commit 739ae47 with commit message:
~~MB-47591~~: [BP] Set the number of schedulers for ...

Couchbase Build Team added a comment - 06/May/22 9:59 PM Build couchbase-server-7.2.0-1120 contains ns_server commit 739ae47 with commit message: MB-47591 : [BP] Set the number of schedulers for ...

Couchbase Build Team added a comment - 06/May/22 9:59 PM

Build couchbase-server-7.2.0-1120 contains ns_server commit af54ca2 with commit message:
~~MB-47591~~: [BP] [babysitter] Set COUCHBASE_CPU_COUNT when starting

Couchbase Build Team added a comment - 06/May/22 9:59 PM Build couchbase-server-7.2.0-1120 contains ns_server commit af54ca2 with commit message: MB-47591 : [BP] [babysitter] Set COUCHBASE_CPU_COUNT when starting

Couchbase Build Team added a comment - 06/May/22 9:59 PM

Build couchbase-server-7.2.0-1120 contains ns_server commit b203ea1 with commit message:
~~MB-47591~~: [BP] Move basic sigar functions to sigar.erl ...

Couchbase Build Team added a comment - 06/May/22 9:59 PM Build couchbase-server-7.2.0-1120 contains ns_server commit b203ea1 with commit message: MB-47591 : [BP] Move basic sigar functions to sigar.erl ...