Thanks for the info Vinoth / Balaji. To me it feels a split between easier-to-understand design and current-implementation. I feel it is simpler to reason (based on how file systems work in general) that restoreToInstant is a complete point-in-time shift to the past (like restoring a file system from a snapshot/backup).
If I have restored the Table to commitTime=005, then having any instants with commitTime > 005 are confusing as it implies that even though my table is at an older time, some future operations will be applied onto it at some point. I will have to read more about incremental timeline syncing and timeline server to understand how it uses the clean instants. BTW, the comment on the function HoodieWriteClient::restoreToInstant reads "NOTE : This action requires all writers (ingest and compact) to a table to be stopped before proceeding". So probably the embedded timeline server can recreate the view next time it comes back up? Thanks Prashant On Wed, Mar 18, 2020 at 11:37 AM Balaji Varadarajan <v.bal...@ymail.com.invalid> wrote: > Prashanth, > I think we should not be reverting clean operations here. Cleans are done > on the oldest file slices and a restore/rollback is not completely undoing > the work of clean that happened before it. > For incremental timeline syncing, embedded timeline server needs to read > these clean metadata to sync its cached file-system view. > Let me know your thoughts. > Balaji.V > On Wednesday, March 18, 2020, 11:23:09 AM PDT, Prashant Wason > <pwa...@uber.com.invalid> wrote: > > HI Team, > > I noticed that when a table is restored to a previous commit ( > HoodieWriteClient::restoreToInstant > < > https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_apache_incubator-2Dhudi_blob_master_hudi-2Dclient_src_main_java_org_apache_hudi_client_HoodieWriteClient.java-23L735&d=DwIFaQ&c=r2dcLCtU9q6n0vrtnDw9vg&r=c89AU9T1AVhM4r2Xi3ctZA&m=ASTWkm7UUMnhZ7sBzpXGPkTc1PhNTJeO7q5IXlBCprY&s=43rqua7SdhvO91hA0ZhOPNQw8ON1nL3bAsCue5o8aYw&e= > >), > only the COMMIT, DELTA_COMMIT and COMPACTION instants are rolled back and > their corresponding files are deleted from the timeline. If there are some > CLEAN instants, they are left over. > > Is there a reason why CLEAN are not removed? Won't they be referring to > files which are no longer present and hence not useful? > > Thanks > Prashant >
