[infinispan-dev] [Cloudtm-discussion] [SPAM] Re: Primary-Backup replication scheme in Infinispan

[Manik Surtani]

On 9 Mar 2011, at 18:58, Paolo Romano wrote:

> On 3/9/11 11:41 AM, Manik Surtani wrote:
>> Paolo,
>> 
>> 
>> On 17 Feb 2011, at 19:51, Paolo Romano wrote:
>> 
>>> First an important premise, which I think was not clear in their previous message. We are here considering the *full replication mode* of Infinispan, in which every node maintains all copies of the same data items. This implies that there is no need to fetch data from remote nodes during transaction execution. Also, Infinispan was configured NOT TO use eager locking. In other words, during transaction's execution Infinispan acquires locks only locally.
>> So are you suggesting that this scheme maintains a single, global master node for the entire cluster, for *all* keys?  Doesn't this become a bottleneck, and how do you deal with the master node failing?
> Hi Manik,
> 
> of course the primary (or master) can become a bottleneck if the number of update transactions is very large. If the % of write transactions is very high, however, then we have to distinguish two cases: low vs high contention.
> 
> At high contention, in fact, the 2PC-based replication scheme used by Infinispan (2PC from now for the sake of brevity ;-) ) falls prey of deadlocks and starts trashing. This is the reasons why 2PC's performance is so poor in the plot attached to Diego and Sebastiano's mail for the case of 1000 keys. Using the primary-backup, being concurrency regulated locally at the primary, and much more efficiently, the actual performace is overall much better.

This is even with deadlock detection enabled?

Cheers
Manik

--
Manik Surtani
manik at jboss.org
twitter.com/maniksurtani

Lead, Infinispan
http://www.infinispan.org