encoder-jvm

Plug-in JVM arguments encoder for servo

Usage

When you will be packaging an adjust driver with JVM settings encoder, please copy encoders/jvm.py to your final package's encoders/ folder. Follow further packaging steps you can find in the repo opsani/servo.

Available settings and their defaults

MaxHeapSize:
  min: 0.5
  step: 1
  unit: 'GiB'

InitialHeapSize:
  min: 0.5
  step: 1
  unit: 'GiB'

InitialEdenHeapSize:
  min: 0.03125
  step: 0.03125
  unit: 'GiB'

GCTimeRatio:
  min: 9
  max: 99
  step: 10
  unit: ''

GCType:
  values:
    - ParNewGC
    - G1GC
    - ParallelOldGC
    - ConcMarkSweepGC

CMSInitiatingOccupancyFraction:
  min: 50
  max: 95
  step: 1
  default: 92

AlwaysPreTouch:
  default: False

CMSParallelRemarkEnabled:
  default: False

CMSScavengeBeforeRemark:
  default: False

ExplicitGCInvokesConcurrent:
  default: False

ParallelRefProcEnabled:
  default: False

ScavengeBeforeFullGC:
  default: False

UnlockExperimentalVMOptions:
  default: False

UseCGroupMemoryLimitForHeap:
  default: False

UseCMSInitiatingOccupancyOnly:
  default: False

UseStringDeduplication:
  default: False

G1NewSizePercent:
    min = 0
    max = 100
    step = 1
    default = 5

G1ReservePercent:
    min = 0
    max = 100
    step = 1
    default = 10

G1MixedGCLiveThresholdPercent:
    min = 0
    max = 100
    step = 1
    default = 65

MaxGCPauseMillis:
    min = 1
    max = 1000
    step = 1
    default = 200

NewRatio:
    min = 1
    max = 99
    step = 1
    default = 2

SurvivorRatio:
    min = 1
    max = 99
    step = 1
    default = 8

TargetSurvivorRatio:
    min = 9
    max = 99
    step = 1
    default = 50

StackShadowPages:
    min = 0
    max = 100
    step = 1
    default = 20

Important notes on configuring settings

For GCTimeRatio configurable options min, max and step can only be within the range of default values. Where step can be only a multiple of a default step value. Ex. if default step is 1.5, configured step has to be one of its multiples: 3, 4.5, 6 and so on.

For GCType configurable option values can only contain a subset of defaults.

For MaxHeapSize InitialHeapSize and InitialEdenHeapSize option max is unknown and has to be configured by the user.

For all the range settings option step has to allow the setting to get from min to max in equal incremental steps. Ex. if min is 7 and max is 32, step can be only 1, 5 or 25.

All the provided settings above will be likely configurable under the key settings of the driver configuration file in a particular place of use of the JVM arguments encoder. Ex. for servo-k8s driver you can set them at command: encoder: settings in a particular component in the driver config file.

How to run tests

Prerequisites:

• Python 3.5 or higher
• PyTest 4.3.0 or higher

Follow these steps:

1. Pull the repository
2. Copy base.py from https://github.com/opsani/servo/tree/master/encoders to folder encoders/
3. Run pytest from the root folder