ProcCgroupDiscoverer (druid-processing 28.0.1 API)

java.lang.Object
- org.apache.druid.java.util.metrics.cgroups.ProcCgroupDiscoverer

All Implemented Interfaces:: CgroupDiscoverer

public class ProcCgroupDiscoverer
extends Object
implements CgroupDiscoverer

- Constructor Summary
  
  Constructors
  Constructor Description
  
  ProcCgroupDiscoverer(Path procDir)
  Create a proc discovery mechanism based on a `/proc` directory.
- Method Summary
  
  All Methods Instance Methods Concrete Methods
  Modifier and Type Method Description
  
  Path discover(String cgroup)
  Gets the path in the virtual FS for the given cgroup (cpu, mem, etc.).
  - Methods inherited from class java.lang.Object
    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ProcCgroupDiscoverer
```
public ProcCgroupDiscoverer(Path procDir)
```
    Create a proc discovery mechanism based on a `/proc` directory.
    
    Parameters:
    
    procDir - The directory under proc. This is usually `/proc/self` or `/proc/#pid`
- Method Detail
  - discover
```
public Path discover(String cgroup)
```
    Gets the path in the virtual FS for the given cgroup (cpu, mem, etc.). The method first retrieves 2 paths: - The cgroup virtual FS mount point by calling /proc/mounts. This is usually like '/sys/fs/cgroup/cpu'. - The heirarchy path by calling /proc/[pid]/cgroup. In Docker this can look like '/docker/4b053f1267369a19dcdcb293e1b4d6b71fd0f26bf7711d589f19d48af92e6278' The method then tries to find the final virtual FS path by contenating the 2 paths first, and then falling back to the root virtual FS path. In this example, the method tries '/sys/fs/cgroup/cpu/docker/4b053f1267369a19dcdcb293e1b4d6b71fd0f26bf7711d589f19d48af92e6278' and then falls back to '/sys/fs/cgroup/cpu'. An exception is thrown if neither path exists.
    
    Specified by:
    
    discover in interface CgroupDiscoverer
    
    Parameters:
    
    cgroup - The cgroup.
    
    Returns:
    
    the virtual FS path.