maobaolong commented on pull request #920: URL: https://github.com/apache/hadoop-ozone/pull/920#issuecomment-630185763
@elek Thank you for watching my PR. I have read the mail list link you give me before, and i agree this approach is one of the approach to solve the multi replication factor support, i think there are no conflict between my PR and the storage-class approach. This PR aimed to remove the limitation of replication factor through protocol, instead, i use an integer type to transfer the replication factor from client to server, if we want to set up some limitation, we can use some new configuration. i think this PR is one the way to the storage-class approach. Lets talk about the storage-class. - if we set the storage class like this (RATIS/THREE --> CLOSED/TWO), not sure if we should define a message StorageClass in the proto file which also contains replicationType and replicationFactor, if this design follow this PR, it can be (RATIS/3 --> CLOSED/2). - BTW, i think (RATIS/THREE --> CLOSED/TWO) is a good idea to follow the ratis way, but it bring a extra replica writing work during the put operation, for write performance of replication factor TWO, Ozone can be slower than HDFS does. - About (RATIS/ONE --> CLOSED/TWO). It is another idea, it looks pretty for performance, but for data redundancy, i think it really bring some losing data risk between the ONE->TWO. So, i think storage-class approach is a good approach, but we should have more discussion work for its design, after that, it can be a pretty approach. And my proposal of this PR only want to open limitation of replication factor, the following work is support more replication factor while writing directly. If fact, i have proved Ozone can write 2 replica directly through ratis in my private branch, i will push more PR after this PR. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
