[ https://issues.apache.org/jira/browse/HBASE-20952?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16632097#comment-16632097 ]
Josh Elser commented on HBASE-20952: ------------------------------------ {quote}Yeah, sorry, I'm lost on what the doc is supposed to be doing. {quote} >From the chatter above on this issue, the request was that a document first be >presented which outlines how HBase uses WALs and idiosyncrasies/gotchas around >that usage. The premise being: if we don't understand how we use WALs, we >can't make a proposal around what "ideal" is. The structure of the document was that, for each section, we covered how it works now and then made a proposal if there was something obvious that should be done instead. Obviously, emphasis is more on the former than the latter (given the immediately above acknowledgements) Thanks for reviewing. > Re-visit the WAL API > -------------------- > > Key: HBASE-20952 > URL: https://issues.apache.org/jira/browse/HBASE-20952 > Project: HBase > Issue Type: Improvement > Components: wal > Reporter: Josh Elser > Priority: Major > Attachments: 20952.v1.txt > > > Take a step back from the current WAL implementations and think about what an > HBase WAL API should look like. What are the primitive calls that we require > to guarantee durability of writes with a high degree of performance? > The API needs to take the current implementations into consideration. We > should also have a mind for what is happening in the Ratis LogService (but > the LogService should not dictate what HBase's WAL API looks like RATIS-272). > Other "systems" inside of HBase that use WALs are replication and > backup&restore. Replication has the use-case for "tail"'ing the WAL which we > should provide via our new API. B&R doesn't do anything fancy (IIRC). We > should make sure all consumers are generally going to be OK with the API we > create. > The API may be "OK" (or OK in a part). We need to also consider other methods > which were "bolted" on such as {{AbstractFSWAL}} and > {{WALFileLengthProvider}}. Other corners of "WAL use" (like the > {{WALSplitter}} should also be looked at to use WAL-APIs only). > We also need to make sure that adequate interface audience and stability > annotations are chosen. -- This message was sent by Atlassian JIRA (v7.6.3#76005)