90ea4506ca
* Fix issue #761: ThreadSafeDoubleCheckLocking.java: Instantiating by Reflection call will be successful if you do that firstly * Create leader election module * Create Interface of Instance and MessageManager * Create implementations with token ring algorithm * Change package structure. Create basic message system. * Implement heartbeat and heartbeat invoking message system * Implement election message handler * Add leader message handler * Add main entry point * Add comments * Update README.md * Fix checkstyle issue * Add Unit Tests * Add Unit Tests * Add bully leader selection * Change System.out to log print. Add MIT license in each file. * Add More java doc comments * Add unit test * Add unit tests
1.5 KiB
1.5 KiB
layout, title, folder, permalink, categories, tags
| layout | title | folder | permalink | categories | tags | ||
|---|---|---|---|---|---|---|---|
| pattern | Leader Election | leader-election | /patterns/leader-election/ | Other |
|
Intent
Leader Election pattern is commonly used in cloud system design. It can help to ensure that task instances selec the leader instance correctly and do not conflict with each other, cause contention for shared resources, or inadvertently interfere with the work that other task instances are performing.
Applicability
Use this pattern when
- the tasks in a distributed application, such as a cloud-hosted solution, require careful coordination and there is no natural leader.
Do not use this pattern when
- there is a natural leader or dedicated process that can always act as the leader. For example, it may be possible to implement a singleton process that coordinates the task instances. If this process fails or becomes unhealthy, the system can shut it down and restart it.
- the coordination between tasks can be easily achieved by using a more lightweight mechanism. For example, if several task instances simply require coordinated access to a shared resource, a preferable solution might be to use optimistic or pessimistic locking to control access to that resource.