/**
* Perform recovery on commit logs located in the directory specified by the config file.
*
* @return the number of mutations replayed
*/
public int recover() throws IOException {
// If createReserveSegments is already flipped, the CLSM is running and recovery has already
// taken place.
if (allocator.createReserveSegments) return 0;
// Allocator could be in the process of initial startup with 0 active and available segments. We
// need to wait for
// the allocation manager to finish allocation and add it to available segments so we don't get
// an invalid response
// on allocator.manages(...) below by grabbing a file off the filesystem before it's added to
// the CLQ.
allocator.allocatingFrom();
FilenameFilter unmanagedFilesFilter =
new FilenameFilter() {
public boolean accept(File dir, String name) {
// we used to try to avoid instantiating commitlog (thus creating an empty segment ready
// for writes)
// until after recover was finished. this turns out to be fragile; it is less
// error-prone to go
// ahead and allow writes before recover(), and just skip active segments when we do.
return CommitLogDescriptor.isValid(name) && !allocator.manages(name);
}
};
// submit all existing files in the commit log dir for archiving prior to recovery -
// CASSANDRA-6904
for (File file :
new File(DatabaseDescriptor.getCommitLogLocation()).listFiles(unmanagedFilesFilter)) {
archiver.maybeArchive(file.getPath(), file.getName());
archiver.maybeWaitForArchiving(file.getName());
}
assert archiver.archivePending.isEmpty()
: "Not all commit log archive tasks were completed before restore";
archiver.maybeRestoreArchive();
File[] files =
new File(DatabaseDescriptor.getCommitLogLocation()).listFiles(unmanagedFilesFilter);
int replayed = 0;
if (files.length == 0) {
logger.info("No commitlog files found; skipping replay");
} else {
Arrays.sort(files, new CommitLogSegmentFileComparator());
logger.info("Replaying {}", StringUtils.join(files, ", "));
replayed = recover(files);
logger.info("Log replay complete, {} replayed mutations", replayed);
for (File f : files) allocator.recycleSegment(f);
}
allocator.enableReserveSegmentCreation();
return replayed;
}
private static CommitLog construct() {
CommitLog log =
new CommitLog(DatabaseDescriptor.getCommitLogLocation(), CommitLogArchiver.construct());
MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
try {
mbs.registerMBean(log, new ObjectName("org.apache.cassandra.db:type=Commitlog"));
} catch (Exception e) {
throw new RuntimeException(e);
}
return log.start();
}
