[Linux-cluster] Back to the problem of unicity of cluster_id

Alain Moulle Alain.Moulle at bull.net
Fri May 4 08:47:35 UTC 2007


Hi
About the problem of unicity of cluster_id generated by cnxman (see a
copy of my old email on the ML just below), is there something fixed
in new versions (U5?) ? or is there a possibility to set a cluster_id
directly in cluster.conf instead of the cluster_name ?
Thanks
Alain
---------------------------------------------------------------------
There is a problem of unicity of cluster_id :

I have a big configuration with lots of CS4 clusters in pairs.
The cluster_names are such as :
iocell1 for first pair
iocell2 for 2nd one
...

Naming is automatic as there are lots of HA node pairs.

ok, now let's take the cluster iocell13 and iocell21 and the
algorythm in cnxman.c :

static uint16_t generate_cluster_id(char *name)
{
        int i;
        int value = 0;

        for (i=0; i<strlen(name); i++) {
                value <<= 1;
                value += name[i];
        }
        return value & 0xFFFF;
}

For iocell13 :
[[[[[[["i"/0x69]*2+"o"/0x6f]*2+"c"/0x63]*2+"e"/0x65]*2+"l"/0x6c]*2+&qu
ot;l"/0x6c]*2+"1"/0x31]*2+"3"/0x33 == 0x6895 == 26773).

and for iocell21:
[[[[[[["i"/0x69]*2+"o"/0x6f]*2+"c"/0x63]*2+"e"/0x65]*2+"l"/0x6c]*2+&qu
ot;l"/0x6c]*2+"2"/0x32]*2+"1"/0x31 == 0x6895 == 26773).

so we have two identical cluster_id for two different cluster
(based on cluster names).

So there is problem because a node denies/un-acks the joins since the same
"cluster-id" is claimed but with an other Cluster name also checked

I've checked that algorythm has not been modified since U2 , and therefore
the problem remains for sure with U4.

Any idea to solve it for sure ?

Thanks
Alain
-- 



mailto:Alain.Moulle at bull.net
+------------------------------+--------------------------------+
|	Alain Moullé	       	| from France :	04 76 29 75 99  |
|                              	| FAX number  : 04 76 29 72 49  |
| Bull SA		       	|				|
| 1, Rue de Provence  		| Adr  : FREC B1-041            |
| B.P. 208			|				|
| 38432 Echirolles - CEDEX     	| Email: Alain.Moulle at bull.net  |
| France                       	| BCOM : 229 7599               |
+-------------------------------+-------------------------------+





More information about the Linux-cluster mailing list