Re: [jgroups-users] In which case Rsp could be null?

No, a Rsp element in  RspList should *never* be null, as a request to 
A,B,C creates a RspList with 3 Rsp objects before even sending the RPC.
It would be very good if you could reproduce this in a simple test...

On 06/04/16 19:46, Questions/problems related to using JGroups wrote:
> I use version 3.6.7.
> The cluster had 35 nodes when the error happened, but it was under heavy
> load. I guess the node got out of the cluster, and was thinking it is
> alone)) because this error happens periodically, often, but not always.
> By design, the cluster is very chatty. Each node sends requests to every
> other node if the file exists on it. So, there are 34 such RPC call was
> made, and I'm guessing, none of them got respond in 5 seconds, as it is
> configured.
> I guess I could increase the timeout for this case, if the cluster grows.
>
> Thank you for your quick response.
> Eugene
>
>
> On Wed, Apr 6, 2016 at 12:15 PM, Questions/problems related to using
> JGroups <[email protected]
> <mailto:[email protected]>> wrote:
>
>     Hi Eugene
>
>     MessageDispatcher.cast (which is used by
>     RpcDispatcher.callRemoteMethods) will return null if
>     real_dests.isEmpty(). In your case, that would happen if the cluster
>     has a single member.
>
>     Cheers
>     Dan
>
>
>     On Wed, Apr 6, 2016 at 6:32 PM, Questions/problems related to using
>     JGroups <[email protected]
>     <mailto:[email protected]>> wrote:
>      > Hello,
>      >
>      > I use RPC, and getting NullPointerException in very unusual place:
>      >
>      > Here is my code example:
>      >
>      > -----------------
>      >
>      > RspList<Boolean> result = dispatcher.callRemoteMethods(null,
>     "fileExists",
>      > new Object[] { localFileName }, new Class[] { String.class },
>      > OPT_ALL_IN_5_SEC);
>      >
>      > for (Rsp<Boolean> rsp : result.values()) {
>      >
>      > if (rsp.getValue()) {
>      >
>      > -------------------
>      >
>      > the last line sometimes throws NPE. Looks like rsp is null.
>      >
>      > The fileExists method returns primitive boolean, so the result
>     cannot be
>      > null by definition.
>      >
>      > Looks like something went wrong during the cluster communication.
>      >
>      > What could it be?
>      >
>      >
>      > Thanks,
>      >
>      > Eugene
>      >
>      >
>      >
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-- 
Bela Ban, JGroups lead (http://www.jgroups.org)


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