high-availability again

[zorg]

Hi c
ould you give me just some more explaination of what is the stage./ 
files used during LMTP delivery have unique filenames
so if i underdstand what you saying. if the stage./ files used during 
LMTP delivery is the same for all the node of the cluster share the same 
SAN then there won't be any problem

thank

Ben Carter a écrit :

> Dave McMurtrie wrote:
>
>> Amos wrote:
>>
>>> What sort of changes did you have to make?
>>
>>
>>
>> We just had to change map_refresh() to call mmap() with MAP_PRIVATE 
>> instead of MAP_SHARED.  Since mmap() is being called with PROT_READ 
>> anyway, this doesn't affect the operation of the application since 
>> the mapped region can never be updated.  Veritas CFS was not very 
>> efficient about maintaining cache coherency across all cluster nodes 
>> when we were using MAP_SHARED.  Everything worked, but under heavy 
>> load it became extremely slow.
>>
> Actually, the important code change for any active/active cluster 
> configuration is to make sure the stage./ files used during LMTP 
> delivery have unique filenames across the cluster.
>
> There are some other setup differences related to this same issue such 
> as symlinking /var/imap/proc, /var/imap/socket, and if you care 
> /var/imap/log to local filesystem space on each cluster node.  You 
> could make these filenames unique across the cluster with code changes 
> if you want to make the code changes for these also.
>
> We added a "clusternode" parameter to imapd.conf to accomplish this 
> for the LMTP stage./ files.
>
> Otherwise, it just worked.
>
> Ben
>

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