Advanatge / Disadvantage of local replicas

[Smudge1977]

We are about to roll Notes/Domino for the first time. What are the advantages / disadvantages to having desk top machines with local replicas of users mail files?
Local replica:

Lower network band width usage - maybe useful in some branch offices remote from where the servers will be located.
Dosent matter in offices with servers as 100Mb switched to the desktop and 1Gb backbone.
Uses more disk space on the client - plenty free anyway.

Do you have corruption problems with all your clients running local replicas. What about replication intervals - will that end up being a bit like how often you do a "Get Massage" in netscape - ie. EMail is not instant but can take 5 - 10 Mins.

Some users currently have netscape folders in excess of 500Mb so each replication will slow there machine down to a snail's pace for some time.

Thouights please!

 

[Packet7]

I would recommend using local replicas on laptops and in remote offices (WAN connections). On your LAN, configure the location documents to point to the server.

To minimize the risk of corruption, I would use a quota policy and provide your users with archive DB's.

Your local users will probably complain of delivery time on new mail. This can be corrected by showing them how to force replication (Send and Receive), from the replicator page.

Hope this helps.


John Judge
MCSE, MCSA, MCP, CCNA, CNA, Network +, A+

 

[Smudge1977]

Would it not be a good thing to reduce network traffic to have local replicas?

What I really need is a good reason not to as the director of IT thinks this is a fantastic idea, but we know it would end up been a pain but have not got any really good jusification!!

 

[pmonett]

Local replicas will only reduce network traffic if users are well trained to replicate new mail before opening it.
Such can be the company policy, but there is strictly no way to enforce such a policy.
For users in the office connected to the LAN and using the "Office" location, I seriously doubt that a local replica is going to lower bandwidth in any way.
First off, the Notes client is still going to query the server for new mail notifications. If the user replicates or goes to the server to read the mail, you'll be using bandwidth. If the user goes back to read the mail again, you'll be using double the bandwidth. Only if the user replicates and reads locally will you be avoiding too much bandwidth usage.
Then again, a little 16Kb mail is not going to choke a 100Mb LAN, I think. What might be an issue is if everyone systematically sends replies with the previous reply attached.
Personally, I think bandwidth saving is much more feasible if users are trained to Reply only, and not Reply with History unless absolutely necessary. I cannot even begin to count the number of times I have seen replies containing at least twenty levels of history with an attachment at the bottom (like 1.3Mb Powerpoint, for instance). Now THAT is what takes up the bandwidth, not the fact that your mail is stored on the server.
If it was up to me, I'd remove the Reply with History option competely. Too many people do it without thinking (like so much else).

 

[AmazingDominik]

Hi,

Local replica's will usually not reduce network traffic, instead they will sometimes increase it.

Every e-mail is sent over the network anyway. Replicating or opening it will cause about the same traffic.
Only when users open attachments multiple times you will have an advantage.

However: the peaks you will have on your server and network each time all these machines will replicate will cause you a lot more trouble!
You will have to activate a lot of replicators to serve all of these users and that will impact server performance. (A standard setup replicates databases one after the other, you will need to add more replictaor tasks).

In the end people will feel the network slowing down.
Without replication you have about a constant load on the network and users get used to it.
With replication you will have a bit more speed on average but now and then you can get huge bottlenecks that slow down the network for 30 minutes for example. Users will find this more annoying.

Example: suppose I receive and open an e-mail of 100K every minute. This puts a constant load of 100K per minute.
Now suppose I replicate every 20 minutes. I will suddenly pull 2 MB at once over the network!

The standard advice is: only replicate if you really need to. That means: mobile users only and server to server replication. NEVER use a replica as a backup. Desktop machines should NEVER use local replia's.
This will also take away a major headache for your helpdesk people because a setup with local replica's will generate lots of questions about delays, replication problems, doclinks that do not work, etc.

Multi user setup on a machine will be more difficult also.

Today more and more companies want to get rid of the Notes Client. No more software on the machines, only web browsers! With Domino, iNotes and some good web-based Notes databases this is possible.
Managing a complex Notes Client with all these options is a big task. Adding replication only adds the complexity of managing these clients.



Kind regards,

Dominik Malfait
dominik@amazingit.com

http://www.amazingit.com

 

[Edgar71]

According to IBM, you will use 40% less bandwidth if using a local replica for mail users. That's an average mail user.

How much you will save depends on what kind of connection you have. If you have 500 users on a 1 gbit LAN there's no point really to use local replicas. But if there's a lot of users in a mixed environment (WAN, LAN, Dial-up), it could be an good idea to use local replicas for at least some users.

You should check out Domino 6, with network compression you can save up to 50% bandwidth (compared to Domino 5).

More details -->

http://www-10.lotus.com/ldd/today.n...1c4bc125e871f15300256c0700599ee9?OpenDocument

 

[Smudge1977]

Thanks for all your responses

How would you intergrate INotes? ie. MS Word, File, Send To and Working on the trains and the like - not sure INOtes is always the best....???
Also you would need big boxes to generate all the HTML.