ServiceHostLogServiceDocumentation

Overview

The service host log service exposes the process logs as a structured JSON response through GET.

Configuration

java.util.logging must be configured with a FileHandler, for example:

java.util.logging.FileHandler.pattern=/var/log/dcpHost.%g.log

The ServiceHost can be configured to use a FileHandler by pointing to a config file:

$ java -Djava.util.logging.config.file=contrib/dcpHostLogging.config -jar dcp-host/target/dcp-host-*-with-dependencies.jar

REST API

URI Path

core/management/process-log

GET

The service defaults to returning every line in the current log file:

$ curl http://localhost:8000/core/management/process-log

Use the lineCount param to limit the number of log file lines:

$ curl http://localhost:8000/core/management/process-log?lineCount=5
{
  "items": [
    "[1][I][1411747104016][DecentralizedControlPlaneHost:8000][allocateExecutor][New executor for service /core/document-index]",
    "[2][I][1411747104179][ServiceHost][findListenPort][port candidate:58571]",
    "[3][I][1411747104181][ServiceHost][findListenPort][port candidate:58572]",
    "[4][I][1411747104182][8000/core/node-groups/default][startSerfAgentProcess][starting serf agent: /Users/dougm/vmw/dcp/bin/serf_darwin agent -bind\u003d0.0.0.0:58572 -rpc-addr\u003d127.0.0.1:58571 -node\u003dc6b0a327-ee75-4323-9063-fc916d55479a -tag /core/node-groups/default\u003dhttp://localhost:8000/core/node-groups/default]",
    "[5][W][1411747104509][8000/core/examples][getPeerChildServiceResults][(1735586309)Service has replication enabled but no group specified. Using default group]"
  ],
  "documentVersion": 0,
  "documentUpdateTimeMicrosUtc": 0

Use the logFileNumber param to get an older log file:

$ curl http://localhost:8000/core/management/process-log?logFileNumber=1

Issues

Due to a bug in JRE8, you must manually remove the log .lck files after shutting down:

$ rm dcpHost.*.log.lck