Re: Enterprise Replication Speed

>Hi All, > > We're thinking about using ER to replicate a couple of tables to 4 sites >around the world (literally). We're thinking of an "update anywhere" >scenario. I need to get a sense of the performance. Assuming we can >install the fastest lines available, does anybody have an idea of the >latency time for an insert at one site to get to another site 10,000 Km >away? > > Also, assume an update occurs in Tokyo, a remote server. If New York is >our "central server" and Rio is another of our remote servers, the update >will need to go from Tokyo to New York to Rio, right? So if the time for >each leg is 10 seconds, I'll need to double that for it to get from Tokyo >to Rio. Is this reasonable? > > I know you can't give me exact numbers but approximate, order-of-magnitude >numbers would be helpful. > Your replication speed is greatly dependent on the type of transaction processing that you are doing. If your transactions are rather large, then you will see some degredation. If your transactions tend to be short, then you can see sub-second replay. Basically what happens is ER guarentees that the transaction will be replayed in the same order that the original transaction commit occured. If the transaction is rather large, then it could take a bit of time for that transaction to be transmitted and replayed on the target instance. That means that transactions following a long transaction will be delayed. So the most important thing is to try to keep the transactions fairly short. You can also use replication groups. Basically that allows some parallelism on the target side to be done. Madison Pruet