+1 for merging EC into master branch. Thanks @Uma for putting this together. Kudos to everyone who contributed to this feature!
Best, Rakesh On Tue, Feb 15, 2022 at 1:48 PM Uma gangumalla <umamah...@apache.org> wrote: > Dear Ozone Devs, > > As you may know, we have been actively developing Ozone Erasure Coding > support in a separate branch HDDS-3816-ec. > > We have finished the development of EC key write and read functionality. > The support of offline recovery( Recovering replica from node loss) will be > part of second phase work. > > Since the code has already grown and increasingly started seeing merge > complications, we would like to propose to merge the current EC branch into > master. > > We will file the new JIRA for the second phase of work and continue the > offline recovery work there. > > Details on Changes: > > - > > Most of the EC core logic went to newly extended classes. Key changes > went into EC*OutputStream and EC*InputStream classes for write and read > respectively. Based on replication type, ECPipelineProvider will be > chosen > for creating EC pipelines. > > > > - > > Since we cannot represent the EC replication in the existing replication > factor, we have introduced ECReplicationConfig. The ReplicationConfig > interface is already pushed to master, so it’s not a new idea coming > through this branch merge now. What is newly coming here is the > ECReplicationConfig class which can be used to express EC replication > configuration. > > > > - > > We wanted to provide the support to enable EC at bucket level. To > simplify some complications, we have moved the default replication > configurations from client to server. > > > > - > > Client side replication type and replication factor removed from the > configuration files and introduced the ozone.server.default.replication > and ozone.server.default.replication.type.We would continue to respect > if > one configures at client side explicitly or passed through APIs, > otherwise > server side bucket level properties or server side default configuration > would take effect. > > > > - > > Other than this change, the rest of EC side code should not impact any > of the existing code flows. > > > We have finished documentation JIRA(HDDS-6172) for covering this feature > and we will continue to improve further in master. > > JIRA: HDDS-3816 > > Completed tasks: ~ 90 > > We wanted to cover the following compatibility issue before the merge: > > HDDS-6209: EC: [Forward compatibility issue] New client to older server > could fail due to the unavailability for client default replication config > > Few other JIRAs in HDDS-3816 are still open but I believe they're not > blockers for merge. > > In short what you can do now with this feature: > > - > > You can enable EC at bucket level and cluster level. > > How to enable it at bucket level? Just create the bucket by passing the ec > replication options. > > - > > You can create EC keys and read the same back. > - > > You should be able to continue writing even when chosen nodes are > failing. (Of Course minimum of Data+Parity live nodes should be > available > in cluster for complete the write) > - > > You should be able to read the file back even if a few nodes failed in > the same ec block group(Failures should not be more than parity number > of > nodes.). > > What is pending? Offline recovery of lost/missing EC containers. As > mentioned above, post merge of this branch, I will create a separate JIRA > for starting the work for OfflineRecovery. > > > There are automated acceptance test cases already added. HDDS-6231 > > In addition to that, we have also performed basic Acceptance Testing in > physical cluster: > > 1. > > Installed 10 nodes cluster and created EC bucket (3:2). > > Uploaded 10GB key. > > Downloaded the same key and checked the md5sum. > > > 1. > > Uploaded 8GB key. > > Downloaded the same key and checked the md5sum. > > > 1. > > Uploaded 3MB key > > Downloaded the same and verified md5sum. > > > 1. > > Changed bucket to (6:3) > > Uploaded 8GB key > > Download the same. > > Also verified the new key should be in 6:3 policy and old keys must be 3:2. > > > > 1. > > Verified with several different size key writes and reads. > > > Merge checklist items assessment is here: > > https://cwiki.apache.org/confluence/display/OZONE/Ozone+EC+Branch%28HDDS-3816-ec%29+Phase-1+%3A+Merge+Checklist > > Big shoutout to Stephen O'Donnell <sodonn...@cloudera.com>, Istvan Fajth > <pi...@cloudera.com> for great efforts in core development and also thanks > a lot to Sammi, Mingchao Zhao, Mark Gui, Kaijie for collaborating on some > of the EC tasks. > > Thanks to Marton for design discussion and on some dev tasks as well. > > Thanks to many others who were involved in design discussions, Arpit, Sidd, > Jitendra, Mukul, Sanjay, Karthik, Bharat, Nanda, Shashi, Prashanth, Rakesh, > Yiqun Lin. > Sorry if I miss anyone here, but your efforts are much appreciated. Without > your tremendous help, we would have not reached this position yet. > > If there are no objections for the merge, I will start the official vote > later. > > Regards, > > EC Branch Devs >
