[YARN-6358] Cache the resolved hosts prevent calls to InetAddress.getByName and normalizeHost

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: resourcemanager, security
• Labels: performance
• Assignee: Jose Miguel Arreola
• Reporter: Jose Miguel Arreola
• Created: 16/Mar/17 23:01
• Updated: 03/Apr/17 22:55

Description

When running performance tests, we noticed that a lot of time is taken in resolving the host address.
In our specific scenario, we saw the function org.apache.hadoop.security.SecurityUtil.getInetAddressByName taking a lot of time to resolve the hosts, and the same function is called a lot of times.
I saw that org.apache.hadoop.yarn.server.resourcemanager.NodesListManager has a cached resolver already because of the same reason.
So, the proposal is, to make this cache generic and use it to save some time in this functions that we already know, but have it available so the cache can be used anywhere else.