THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
Design details and discussion for KNOX-88
Definition
Knox HA is a set of routines for transparent work with Hadoop service that stands in HA mode.
Purpose of Knox HA service
- Automatic failover. (Example: switch request from not responding name-node to active name-node.)
- Pluggable support of failover strategies.
- Daemon-service for regular ping of Hadoop service state (Performance optimization to keeping actual state of service).
Topology
<topology>
<gateway>
...
<provider>
<role>ha</role>
<name>HAProvider</name>
<param>
<name>webhdfs.ha</name>
<value>failover_strategy=BaseStrategy;retryCount=3;timeoutInterval=5000;enabled=true</value>
</param>
</provider>
...
<gateway>
...
<service>
<role>WEBHDFS</role>
<url>machine1.example.com:50070</url>
<url>machine2.example.com:50070</url>
</service>
...
<service>
<role>NAMENODE</role>
<url>machine1.example.com:50070</url>
<url>machine2.example.com:50070</url>
</service>
...
</topology>
Example UML
Example Code Block
Code Title
class X {
}