[IGNITE-16150] Get rid of redundant copying of files after downloading when restoring a snapshot.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.12
• Fix Version/s: 2.13
• Labels: iep-43 ise ise.lts
• Release Note: Improved snapshot partitions move
• Ignite Flags: Release Notes Required
• Assignee: Pavel Pereslegin
• Reporter: Pavel Pereslegin
• Created: 17/Dec/21 11:24
• Updated: 06/Oct/22 18:47
• Resolved: 21/Jan/22 09:12

Description

During the snapshot restore procedure after retrieving the partition file from the remote node, we create an additional copy of this file.

	for (Map.Entry<UUID, Map<Integer, Set<Integer>>> m : snpAff.entrySet()) {
		ctx.cache().context().snapshotMgr()
			.requestRemoteSnapshotFiles(m.getKey(),
				opCtx0.snpName,
				m.getValue(),
				opCtx0.stopChecker,
				(snpFile, t) -> {
					...

					Path partFile = Paths.get(tmpCacheDir.getAbsolutePath(), snpFile.getName());

					try {
						IgniteSnapshotManager.copy(snpMgr.ioFactory(),
							snpFile,
							partFile.toFile(),
							snpFile.length());
					...

File copying is redundant here and can have significant performance overhead.

Instead, we have to download the file to the target directory (and rename it to the desired name if necessary).

Issue Links

• links to: GitHub Pull Request #9724
• links to: TC run all