Hi Nikolai,
I looked at the code for this method earlier (reproduced below)...the UUID
is generated once (via VM_ID) per cluster node JVM & the atomic long again
is local to the cluster node JVM (unlike the *igniteAtomicSequence*). Do
you think its still okay to use it...i thought we at least need the
*igniteAtomicSequence *for cluster level uniqueness...
/** VM ID. */
public static final UUID VM_ID = UUID.randomUUID();
public static IgniteUuid randomUuid() {
return new IgniteUuid(VM_ID, cntGen.incrementAndGet());
}
Regards,
Muthu
On Tue, Jun 13, 2017 at 6:32 AM, Nikolai Tikhonov <[email protected]>
wrote:
> Muthu,
>
> Look at Ignite Uuid#randomUuid() method. I think it will provide needed
> guarantees for your case.
>
> On Mon, Jun 12, 2017 at 9:53 PM, Muthu <[email protected]> wrote:
>
>> Thanks Nikolai..this is what i am doing...not sure if this is too
>> much..what do you think..the goal is to make sure that a UUID is unique
>> across the entire application (the problem is each node that is part of the
>> cluster would be doing this for different entities that it owns)
>>
>> ...
>> ...
>> System.out.println("==== in ObjectCacheMgrService.insertDepartment ====
>> for dept : " + dept);
>> long t1 = System.currentTimeMillis();
>> *String uUID = new IgniteUuid(UUID.randomUUID(),
>> igniteAtomicSequence.incrementAndGet()).toString();*
>> long t2 = System.currentTimeMillis();
>> System.out.println("Time for UUID generation (millis) : " + (t2 - t1));
>> *dept.setId(uUID);*
>> * deptCache.getAndPut(uUID, dept);*
>> System.out.println("==== in ObjectCacheMgrService.insertDepartment :
>> department ==== inserted successfully : " + dept);
>> ...
>> ...
>>
>> Regards,
>> Muthu
>>
>> On Mon, Jun 12, 2017 at 3:24 AM, Nikolai Tikhonov <[email protected]>
>> wrote:
>>
>>> Muthu,
>>>
>>> Yes, you can use IgniteUUID as unique ID generator. What you will use
>>> depends your requirements. IgniteAtomicSequence takes one long and
>>> IgniteUUID takes 3 long. But getting new range sequence is distributed
>>> operation. You need to decied what more critical for your.
>>>
>>> On Fri, Jun 9, 2017 at 8:46 PM, Muthu <[email protected]> wrote:
>>>
>>>>
>>>> Missed adding this one...i know there is support for ID generation with
>>>> IgniteAtomicSequence @ https://apacheignite.readme.io/docs/id-generator
>>>>
>>>> The question is which one should i use...i want to use this to generate
>>>> unique ids for entities that are to be cached & persisted..
>>>>
>>>> Regards,
>>>> Muthu
>>>>
>>>>
>>>> On Fri, Jun 9, 2017 at 10:27 AM, Muthu <[email protected]>
>>>> wrote:
>>>>
>>>>> Hi Folks,
>>>>>
>>>>> Is it possible to generate a Grid/Cluster unique UUID using
>>>>> IgniteUuid. I looked at the source code & static factory method
>>>>> *randomUuid
>>>>> <https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/lang/IgniteUuid.html#randomUuid%28%29>*().
>>>>> It looks like it generates one with with a java.util.UUID (generated with
>>>>> its randomUUID) & an AutomicLong's incrementAndGet
>>>>>
>>>>> Can i safely assume that given that it uses a combination of UUID &
>>>>> long on the individual VMs that are part of the Grid/Cluster it will be
>>>>> unique or is there a better way?
>>>>>
>>>>> Regards,
>>>>> Muthu
>>>>>
>>>>
>>>>
>>>
>>
>
