io.flamingock.internal.core.external.store.lock.community

Interface CommunityLockService

All Superinterfaces:

LockService

public interface CommunityLockService
extends LockService

Method Summary

Modifier and Type	Method and Description
LockAcquisition	upsert(LockKey key, io.flamingock.internal.util.id.RunnerId owner, long leaseMillis) a) If there is an existing lock in the database for the same key and owner (existingLock.key==newLock.key && existingLoc.owner==newLock.owner), then the lock in database is updated/refreshed with the new values.

Methods inherited from interface io.flamingock.internal.core.external.store.lock.LockService

extendLock, getLock, releaseLock

Method Detail

upsert

LockAcquisition upsert(LockKey key,
                       io.flamingock.internal.util.id.RunnerId owner,
                       long leaseMillis)
                throws LockServiceException

a) If there is an existing lock in the database for the same key and owner (existingLock.key==newLock.key && existingLoc.owner==newLock.owner), then the lock in database is updated/refreshed with the new values. The most common scenario is to extend the lock's expiry date.

b) If there is an existing lock in the database for the same key and different owner, but expired (existingLock.key==newLock.key && existingLock.owner!=newLock.owner && now > expiredAt), the lock is replaced with the newLock, so the owner of the lock for that key is newLock.owner

c) If scenario b, but lock is not expired yet, should throw an LockPersistenceException.

d) If there isn't any lock with key=newLock.key, newLock is inserted.

Parameters:

key - Specially important in cloud execution as it represents a service

owner - It references the running instance

leaseMillis - How long(in millis) the lock will be acquired for.

Returns:

the lockAcquisition with the owner and leaseMillis, among others

Throws:

LockServiceException - if there is a lock in database with same key, but is expired and belong to another owner or cannot insert/update the lock for any other reason