Dear *,
I'd like to solicit some feedback/learned opinion based on your
experience in the following scenario.
Although our application is not time 'critical' we have some
surprising delays.
We are using JDK 1.5_10, JBoss 4.0.5 and EJB (very thin layer!) with
communication from a rich client.
The application seems to suffer from some latency issues when called
between say, London and New York.
That is to be expected but it is not proportional and puzzles us a
bit...
e.g. we have a very very simple EJB that simply does:
byte[] getPayload(int size);
for an array 1,000 bytes, we have a time measured on the client of:
- same machine 6 ms
- same subnet 33 ms
- across VPN to New York ~300 ms
The times are nearly identical for 1 byte and seem very similar for up
to 40KB.
Now a simple PING from DOS command line to NY takes 85~100 ms which,
we are told, is pretty good.
Our current thoughts:
- We were initially using HTTPS (256) for all communications but
reverting to JRMP does NOT seem to improve at all. This surprised us
quite a bit...
- if encryption was the issue, the local or same subnet test should
also show large delays
Questions:
- is this in line with your own experience of RMI call to JBoss across
the Pond?
- How many 'roundtrips' are required by the JRMP protocol for a
single call to the server?
- Any suggestion to speed things up in the current architecture? e.g.
is IIOP faster? or requires less round-trips?
Many thanks!
Benoit
