*USE CASE *- use IgniteAtomicLong for table sequence generation (may not be
correct approach in a distributed environment).
*Ignite Server *(start Ignite as server mode) - apache-ignite-2.8.0.20190215
daily build
*Ignite Service* (start Ignite as client mode) - use Ignite Spring to
initialize the sequence, see code snippet below.
*code snippet*
IgniteAtomicLong userSeq;
@Autowired
UserRepository userRepository;
@Autowired
Ignite igniteInstance;
@PostConstruct
@Override
public void initSequence() {
Long maxId = userRepository.getMaxId();
if (maxId == null)
{ maxId = 0L; }
LOG.info("Max User id: {}", maxId);
userSeq = igniteInstance.atomicLong("userSeq", maxId, true);
userSeq.getAndSet(maxId);
}
@Override
public Long getNextSequence() {
return userSeq.incrementAndGet();
}
*Exception*
This code works well until the Ignite Server restarted (Ignite Service was
not restarted). It raised "Sequence was removed from cache" after Ignite
Server node restarted.
020-08-11 16:14:46 [http-nio-8282-exec-3] ERROR
c.p.c.p.service.PersistenceService - Error while saving entity:
java.lang.IllegalStateException: Sequence was removed from cache: userSeq
at
org.apache.ignite.internal.processors.datastructures.AtomicDataStructureProxy.removedError(AtomicDataStructureProxy.java:145)
at
org.apache.ignite.internal.processors.datastructures.AtomicDataStructureProxy.checkRemoved(AtomicDataStructureProxy.java:116)
at
org.apache.ignite.internal.processors.datastructures.GridCacheAtomicLongImpl.incrementAndGet(GridCacheAtomicLongImpl.java:94)
*Tried to reinitialize when the server node is down. But raises another
exception - "cannot start/stop cache within lock or transaction"*
How to solve such issues? Any suggestions are appreciated.
@Override
public Long getNextSequence() {
if (useSeq == null || userSeq.removed())
{ initSeqence(); }
return userSeq.incrementAndGet();
}
--
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