private void pingSessionBackup(@Nonnull final MemcachedBackupSession session)
throws InterruptedException {
final String key = _sessionIdFormat.createBackupKey(session.getId());
final Future<Boolean> touchResultFuture = _memcached.add(key, 5, 1);
try {
final boolean touchResult =
touchResultFuture.get(_manager.getOperationTimeout(), TimeUnit.MILLISECONDS);
if (touchResult) {
_log.warn(
"The secondary backup for session "
+ session.getIdInternal()
+ " should be touched in memcached, but it seemed to be"
+ " not existing. Will store in memcached again.");
saveSessionBackup(session, key);
} else _log.debug("The secondary session backup was ping'ed successfully.");
} catch (final TimeoutException e) {
_log.warn(
"The secondary backup for session "
+ session.getIdInternal()
+ " could not be completed within "
+ _manager.getOperationTimeout()
+ " millis, was cancelled now.");
} catch (final ExecutionException e) {
_log.warn(
"An exception occurred when trying to ping session " + session.getIdInternal(), e);
}
}
/**
* Invoked after a non-sticky session is loaded from memcached, can be used to update some session
* fields based on separately stored information (e.g. session validity info).
*
* @param lockStatus the {@link LockStatus} that was returned from {@link
* #onBeforeLoadFromMemcached(String)}.
*/
protected void onAfterLoadFromMemcached(
@Nonnull final MemcachedBackupSession session, @Nullable final LockStatus lockStatus) {
session.setLockStatus(lockStatus);
final long start = System.currentTimeMillis();
final SessionValidityInfo info = loadSessionValidityInfo(session.getIdInternal());
if (info != null) {
_stats.registerSince(NON_STICKY_AFTER_LOAD_FROM_MEMCACHED, start);
session.setLastAccessedTimeInternal(info.getLastAccessedTime());
session.setThisAccessedTimeInternal(info.getThisAccessedTime());
} else {
_log.warn("No validity info available for session " + session.getIdInternal());
}
}
@Override
public Void call() throws Exception {
final BackupResult backupResult = _result.get();
if (_pingSessionIfBackupWasSkipped) {
if (backupResult.getStatus() == BackupResultStatus.SKIPPED) {
pingSession(_session, _backupSessionService);
}
}
/*
* For non-sticky sessions we store a backup of the session in a secondary memcached node (under a special key
* that's resolved by the SuffixBasedNodeLocator), but only when we have more than 1 memcached node configured...
*/
if (_storeSecondaryBackup) {
try {
if (_log.isDebugEnabled()) {
_log.debug(
"Storing backup in secondary memcached for non-sticky session " + _session.getId());
}
if (backupResult.getStatus() == BackupResultStatus.SKIPPED) {
pingSessionBackup(_session);
} else {
saveSessionBackupFromResult(backupResult);
}
saveValidityBackup();
} catch (final RuntimeException e) {
_log.info("Could not store secondary backup of session " + _session.getIdInternal(), e);
}
}
return null;
}
private void pingSession(
@Nonnull final MemcachedBackupSession session,
@Nonnull final BackupSessionService backupSessionService)
throws InterruptedException {
final Future<Boolean> touchResult =
_memcached.add(_storageKeyFormat.format(session.getIdInternal()), 5, 1);
try {
if (touchResult.get()) {
_stats.nonStickySessionsPingFailed();
_log.warn(
"The session "
+ session.getIdInternal()
+ " should be touched in memcached, but it does not exist"
+ " therein. Will store in memcached again.");
updateSession(session, backupSessionService);
} else _log.debug("The session was ping'ed successfully.");
} catch (final ExecutionException e) {
_log.warn("An exception occurred when trying to ping session " + session.getIdInternal(), e);
}
}
public void saveSessionBackup(
@Nonnull final MemcachedBackupSession session, @Nonnull final String key)
throws InterruptedException {
try {
final byte[] data = _manager.serialize(session);
final Future<Boolean> backupResult =
_memcached.set(
key, toMemcachedExpiration(session.getMemcachedExpirationTimeToSet()), data);
if (!backupResult.get().booleanValue()) {
_log.warn(
"Update for secondary backup of session "
+ session.getIdInternal()
+ " (after unsuccessful ping) did not return sucess.");
}
} catch (final ExecutionException e) {
_log.warn(
"An exception occurred when trying to update secondary session backup for "
+ session.getIdInternal(),
e);
}
}
public void saveSessionBackupFromResult(final BackupResult backupResult) {
final byte[] data = backupResult.getData();
if (data != null) {
final String key = _sessionIdFormat.createBackupKey(_session.getId());
_memcached.set(
key, toMemcachedExpiration(_session.getMemcachedExpirationTimeToSet()), data);
} else {
_log.warn(
"No data set for backupResultStatus "
+ backupResult.getStatus()
+ " for sessionId "
+ _session.getIdInternal()
+ ", skipping backup"
+ " of non-sticky session in secondary memcached.");
}
}
private void updateSession(
@Nonnull final MemcachedBackupSession session,
@Nonnull final BackupSessionService backupSessionService)
throws InterruptedException {
final Future<BackupResult> result = backupSessionService.backupSession(session, true);
try {
if (result.get().getStatus() != BackupResultStatus.SUCCESS) {
_log.warn(
"Update for session (after unsuccessful ping) did not return SUCCESS, but "
+ result.get());
}
} catch (final ExecutionException e) {
_log.warn(
"An exception occurred when trying to update session " + session.getIdInternal(), e);
}
}
static byte[] serializeSessionFields(final MemcachedBackupSession session) {
final byte[] idData = serializeId(session.getIdInternal());
final byte[] principalData =
session.getPrincipal() != null ? serializePrincipal(session.getPrincipal()) : null;
final int principalDataLength = principalData != null ? principalData.length : 0;
final int sessionFieldsDataLength =
2 // short value for the version
// the following might change with other versions, refactoring needed then
+ 2 // short value that stores the dataLength
+ NUM_BYTES // bytes that store all session attributes but the id
+ 2 // short value that stores the idData length
+ idData.length // the number of bytes for the id
+ 2 // short value for the authType
+ 2 // short value that stores the principalData length
+ principalDataLength; // the number of bytes for the principal
final byte[] data = new byte[sessionFieldsDataLength];
int idx = 0;
idx = encodeNum(CURRENT_VERSION, data, idx, 2);
idx = encodeNum(sessionFieldsDataLength, data, idx, 2);
idx = encodeNum(session.getCreationTimeInternal(), data, idx, 8);
idx = encodeNum(session.getLastAccessedTimeInternal(), data, idx, 8);
idx = encodeNum(session.getMaxInactiveInterval(), data, idx, 4);
idx = encodeBoolean(session.isNewInternal(), data, idx);
idx = encodeBoolean(session.isValidInternal(), data, idx);
idx = encodeNum(session.getThisAccessedTimeInternal(), data, idx, 8);
idx = encodeNum(session.getLastBackupTime(), data, idx, 8);
idx = encodeNum(idData.length, data, idx, 2);
idx = copy(idData, data, idx);
idx = encodeNum(AuthType.valueOfValue(session.getAuthType()).getId(), data, idx, 2);
idx = encodeNum(principalDataLength, data, idx, 2);
copy(principalData, data, idx);
return data;
}
/**
* Is invoked after the backup of the session is initiated, it's represented by the provided
* backupResult. The requestId is identifying the request.
*/
protected void onAfterBackupSession(
@Nonnull final MemcachedBackupSession session,
final boolean backupWasForced,
@Nonnull final Future<BackupResult> result,
@Nonnull final String requestId,
@Nonnull final BackupSessionService backupSessionService) {
if (!_sessionIdFormat.isValid(session.getIdInternal())) {
return;
}
try {
final long start = System.currentTimeMillis();
final int maxInactiveInterval = session.getMaxInactiveInterval();
final byte[] validityData =
encode(
maxInactiveInterval,
session.getLastAccessedTimeInternal(),
session.getThisAccessedTimeInternal());
final String validityKey =
_sessionIdFormat.createValidityInfoKeyName(session.getIdInternal());
// fix for #88, along with the change in session.getMemcachedExpirationTimeToSet
final int expiration = maxInactiveInterval <= 0 ? 0 : maxInactiveInterval;
final Future<Boolean> validityResult =
_memcached.set(validityKey, toMemcachedExpiration(expiration), validityData);
if (!_manager.isSessionBackupAsync()) {
// TODO: together with session backup wait not longer than sessionBackupTimeout.
// Details: Now/here we're waiting the whole session backup timeout, even if (perhaps) some
// time
// was spent before when waiting for session backup result.
// For sync session backup it would be better to set both the session data and
// validity info and afterwards wait for both results (but in sum no longer than
// sessionBackupTimeout)
validityResult.get(_manager.getSessionBackupTimeout(), TimeUnit.MILLISECONDS);
}
if (_log.isDebugEnabled()) {
_log.debug("Stored session validity info for session " + session.getIdInternal());
}
/* The following task are performed outside of the request thread (includes waiting for the backup result):
* - ping session if the backup was skipped (depends on the backup result)
* - save secondary session backup if session was modified (backup not skipped)
* - ping secondary session backup if the backup was skipped
* - save secondary validity backup
*/
final boolean pingSessionIfBackupWasSkipped = !backupWasForced;
final boolean performAsyncTasks = pingSessionIfBackupWasSkipped || _storeSecondaryBackup;
if (performAsyncTasks) {
final Callable<?> backupSessionTask =
new OnAfterBackupSessionTask(
session,
result,
pingSessionIfBackupWasSkipped,
backupSessionService,
_storeSecondaryBackup,
validityKey,
validityData);
_executor.submit(backupSessionTask);
}
_stats.registerSince(NON_STICKY_AFTER_BACKUP, start);
} catch (final Throwable e) {
_log.warn("An error occurred during onAfterBackupSession.", e);
}
}