[ https://issues.apache.org/jira/browse/IGNITE-4337?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15730553#comment-15730553 ]
Dmitriy Setrakyan commented on IGNITE-4337: ------------------------------------------- One more comment. Is the name {{IgniteWriteAheadLogManager}} going to be confusing? We already have *managers* in Ignite which serve a different purpose. How about {{IgniteWriteAheadLogStore}}? > Introduce persistence interface to allow build reliable persistence plugins > --------------------------------------------------------------------------- > > Key: IGNITE-4337 > URL: https://issues.apache.org/jira/browse/IGNITE-4337 > Project: Ignite > Issue Type: Sub-task > Components: general > Reporter: Alexey Goncharuk > Fix For: 2.0 > > > With page memory interface introduced, it may be possible to build a > persistence layer around this architecture. I think we should move the > PageMemory interface itself to {{org.apache.ignite.plugin.storage}} package > and introduce the following interface to allow other components to log it's > activity in crash-resistant way: > {code} > /** > * > */ > public interface IgniteWriteAheadLogManager extends GridCacheSharedManager { > /** > * @return {@code true} If we have to always write full pages. > */ > public boolean isAlwaysWriteFullPages(); > /** > * @return {@code true} if WAL will perform fair syncs on fsync call. > */ > public boolean isFullSync(); > /** > * Resumes logging after start. When WAL manager is started, it will skip > logging any updates until this > * method is called to avoid logging changes induced by the state restore > procedure. > */ > public void resumeLogging(WALPointer lastWrittenPtr) throws > IgniteCheckedException; > /** > * Appends the given log entry to the write-ahead log. > * > * @param entry entry to log. > * @return WALPointer that may be passed to {@link #fsync(WALPointer)} > method to make sure the record is > * written to the log. > * @throws IgniteCheckedException If failed to construct log entry. > * @throws StorageException If IO error occurred while writing log entry. > */ > public WALPointer log(WALRecord entry) throws IgniteCheckedException, > StorageException; > /** > * Makes sure that all log entries written to the log up until the > specified pointer are actually persisted to > * the underlying storage. > * > * @param ptr Optional pointer to sync. If {@code null}, will sync up to > the latest record. > * @throws IgniteCheckedException If > * @throws StorageException > */ > public void fsync(WALPointer ptr) throws IgniteCheckedException, > StorageException; > /** > * Invoke this method to iterate over the written log entries. > * > * @param start Optional WAL pointer from which to start iteration. > * @return Records iterator. > * @throws IgniteException If failed to start iteration. > * @throws StorageException If IO error occurred while reading WAL > entries. > */ > public WALIterator replay(WALPointer start) throws > IgniteCheckedException, StorageException; > /** > * Gives a hint to WAL manager to clear entries logged before the given > pointer. Some entries before the > * the given pointer will be kept because there is a configurable WAL > history size. Those entries may be used > * for partial partition rebalancing. > * > * @param ptr Pointer for which it is safe to clear the log. > * @return Number of deleted WAL segments. > */ > public int truncate(WALPointer ptr); > } > {code} -- This message was sent by Atlassian JIRA (v6.3.4#6332)