mirror of https://github.com/apache/druid.git
501dcb43fa
This is done by killing and respawning the jvms rather than reconnecting to existing jvms, for a couple reasons. One is that it lets you restore tasks after server reboots too, and another is that it lets you upgrade all the software on a box at once by just restarting everything. The main changes are, 1) Add "canRestore" and "stopGracefully" methods to Tasks that say if a task can stop gracefully, and actually do a graceful stop. RealtimeIndexTask is the only one that currently implements this. 2) Add "stop" method to TaskRunners that attempts to do an orderly shutdown. ThreadPoolTaskRunner- call stopGracefully on restorable tasks, wait for exit ForkingTaskRunner- close output stream to restorable tasks, wait for exit RemoteTaskRunner- do nothing special, we actually don't want to shutdown 3) Add "restore" method to TaskRunners that attempts to bootstrap tasks from last run. Only ForkingTaskRunner does anything here. It maintains a "restore.json" file with a list of restorable tasks. 4) Have the CliPeon's ExecutorLifecycle lock the task base directory to avoid a restored task and a zombie old task from stomping on each other. |
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| .. | ||
| broker.md | ||
| caching.md | ||
| coordinator.md | ||
| hadoop.md | ||
| historical.md | ||
| index.md | ||
| indexing-service.md | ||
| logging.md | ||
| production-cluster.md | ||
| realtime.md | ||
| simple-cluster.md | ||
| zookeeper.md | ||