CGroupsManager (Apache UIMA DUCC: uima-ducc-agent 2.2.0 API)

java.lang.Object
- org.apache.uima.ducc.agent.launcher.CGroupsManager

```
public class CGroupsManager
extends Object
```
Manages cgroup container on a node Supported operations: - cgcreate - creates cgroup container - cgset - sets max memory limit for an existing container This code supports both new and old cgconfig. The old configuration adds cgroups to /ducc where the new adds it to: /memory/ducc. On startup the agent detects which cgconfig is active and adjusts accordingly.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`CGroupsManager.CgroupMemoryStat`
`class`	`CGroupsManager.CGroupsException`
`class`	`CGroupsManager.NodeProcessInfo`
`class`	`CGroupsManager.Validator`

Constructor Summary

Constructors
Constructor and Description
`CGroupsManager(String cgroupUtilsDir, String cgroupBaseDir, String subsystems, org.apache.uima.ducc.common.utils.DuccLogger agentLogger, long maxTimeToWaitForProcessToStop)`

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`cgroupExists(String cgroup)`
`void`	`cleanup()` Finds all stale CGroups and cleans them up.
`Set<String>`	`collectExistingContainers()` Return a Set of existing cgroup Ids found in the filesystem identified by 'cgroupBaseDir'.
`void`	`configure(NodeAgent agent)`
`boolean`	`createContainer(String containerId, String userName, String groupName, boolean useDuccSpawn)` Creates cgroup container with a given id and owner.
`boolean`	`destroyContainer(String containerId, String userId, int signal)` Removes cgroup container with a given id.
`String[]`	`getAllCGroupPids()` Returns an array of PIDs managed by cgroups.
`String`	`getCGroupsUtilsDir()` Return location where cgroups utils like cgcreate can be found
`String`	`getContainerId(ManagedProcess managedProcess)`
`long`	`getCpuUsage(String containerId)`
`String`	`getDuccCGroupBaseDir()`
`String[]`	`getPidsInCgroup(String cgroupName)`
`Set<CGroupsManager.NodeProcessInfo>`	`getProcessesOnNode()`
`String`	`getSubsystems()`
`long`	`getUsageForMemoryStat(CGroupsManager.CgroupMemoryStat stat, String containerId)`
`String`	`getUserGroupName(String userName)`
`boolean`	`isCpuReportingEnabled()`
`boolean`	`isPidInCGroup(String pid)`
`void`	`kill(String user, String pid, int signal)`
`static void`	`main(String[] args)`
`boolean`	`setContainerCpuShares(String containerId, String userId, boolean useDuccSpawn, long containerCpuShares)` Sets the cpu shares use for an existing cgroup container.
`boolean`	`setContainerMaxMemoryLimit(String containerId, String userId, boolean useDuccSpawn, long containerMaxSize)` Sets the max memory use for an existing cgroup container.
`boolean`	`setContainerSwappiness(String containerId, String userId, boolean useDuccSpawn, long swappiness)` Sets the memory swappiness for an existing cgroup container.
`CGroupsManager.Validator`	`validator(String cgroupsBaseDir, String containerId, String userName, boolean useDuccling)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CGroupsManager

public CGroupsManager(String cgroupUtilsDir,
              String cgroupBaseDir,
              String subsystems,
              org.apache.uima.ducc.common.utils.DuccLogger agentLogger,
              long maxTimeToWaitForProcessToStop)

Method Detail

main

public static void main(String[] args)

Parameters:: args -

getCGroupsUtilsDir
```
public String getCGroupsUtilsDir()
```
Return location where cgroups utils like cgcreate can be found

Returns:
- absolute path to cgroup utils

configure

public void configure(NodeAgent agent)

validator

public CGroupsManager.Validator validator(String cgroupsBaseDir,
                                 String containerId,
                                 String userName,
                                 boolean useDuccling)
                                   throws Exception

Throws:: Exception

getPidsInCgroup

public String[] getPidsInCgroup(String cgroupName)
                         throws Exception

Throws:: Exception

cleanup
```
public void cleanup()
             throws Exception
```
Finds all stale CGroups and cleans them up. The code only cleans up cgroups folders with names that follow ducc's cgroup naming convention: ... First, each cgroup is checked for still running processes in the cgroup by looking at ///cgroup.proc file which includes PIDs of processes associated with the cgroups. If processes are found, each one is killed via -9 and the cgroup is removed.

Throws:

Exception

isPidInCGroup

public boolean isPidInCGroup(String pid)
                      throws Exception

Throws:: Exception

getAllCGroupPids
```
public String[] getAllCGroupPids()
                          throws Exception
```
Returns an array of PIDs managed by cgroups.

Returns:
- String array of PIDs

Throws:

Exception

kill

public void kill(String user,
        String pid,
        int signal)

getContainerId

public String getContainerId(ManagedProcess managedProcess)

createContainer

public boolean createContainer(String containerId,
                      String userName,
                      String groupName,
                      boolean useDuccSpawn)
                        throws Exception

Creates cgroup container with a given id and owner.

Parameters:: containerId - - new cgroup container id; userId - - owner of the cgroup container; useDuccSpawn - - use duccling to run 'cgcreate' command
Returns:: - true on success, false otherwise
Throws:: Exception

isCpuReportingEnabled

public boolean isCpuReportingEnabled()

getCpuUsage

public long getCpuUsage(String containerId)
                 throws Exception

Throws:: Exception

getUsageForMemoryStat

public long getUsageForMemoryStat(CGroupsManager.CgroupMemoryStat stat,
                         String containerId)
                           throws Exception

Throws:: Exception

setContainerMaxMemoryLimit
```
public boolean setContainerMaxMemoryLimit(String containerId,
                                 String userId,
                                 boolean useDuccSpawn,
                                 long containerMaxSize)
                                   throws Exception
```
Sets the max memory use for an existing cgroup container.

Parameters:
containerId - - existing container id for which limit will be set
userId - - container owner
useDuccSpawn - - run 'cgset' command as a user
containerMaxSize - - max memory limit

Returns:
- true on success, false otherwise

Throws:

Exception

setContainerCpuShares
```
public boolean setContainerCpuShares(String containerId,
                            String userId,
                            boolean useDuccSpawn,
                            long containerCpuShares)
                              throws Exception
```
Sets the cpu shares use for an existing cgroup container.

Parameters:
containerId - - existing container id for which limit will be set
userId - - container owner
useDuccSpawn - - run 'cgset' command as a user
containerCpuShares - - cpu shares

Returns:
- true on success, false otherwise

Throws:

Exception

setContainerSwappiness
```
public boolean setContainerSwappiness(String containerId,
                             String userId,
                             boolean useDuccSpawn,
                             long swappiness)
                               throws Exception
```
Sets the memory swappiness for an existing cgroup container.

Parameters:
containerId - - existing container id for which limit will be set
userId - - container owner
useDuccSpawn - - run 'cgset' command as a user
swappiness - - swappiness

Returns:
- true on success, false otherwise

Throws:

Exception

destroyContainer
```
public boolean destroyContainer(String containerId,
                       String userId,
                       int signal)
                         throws Exception
```
Removes cgroup container with a given id. Cgroups are implemented as a virtual file system. All is needed here is just rmdir.

Parameters:
containerId - - cgroup to remove

Returns:
- true on success, false otherwise

Throws:

Exception

getUserGroupName

public String getUserGroupName(String userName)
                        throws Exception

Throws:: Exception

collectExistingContainers
```
public Set<String> collectExistingContainers()
                                      throws Exception
```
Return a Set of existing cgroup Ids found in the filesystem identified by 'cgroupBaseDir'.

Returns:
- set of cgroup ids

Throws:

Exception

getDuccCGroupBaseDir
```
public String getDuccCGroupBaseDir()
```

getSubsystems
```
public String getSubsystems()
```

cgroupExists

public boolean cgroupExists(String cgroup)
                     throws Exception

Throws:: Exception

getProcessesOnNode

public Set<CGroupsManager.NodeProcessInfo> getProcessesOnNode()
                                                       throws Exception

Throws:: Exception

Class CGroupsManager

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

CGroupsManager

Method Detail

main

getCGroupsUtilsDir

configure

validator

getPidsInCgroup

cleanup

isPidInCGroup

getAllCGroupPids

kill

getContainerId

createContainer

isCpuReportingEnabled

getCpuUsage

getUsageForMemoryStat

setContainerMaxMemoryLimit

setContainerCpuShares

setContainerSwappiness

destroyContainer

getUserGroupName

collectExistingContainers

getDuccCGroupBaseDir

getSubsystems

cgroupExists

getProcessesOnNode