Network Bandwidth between Master and Replica sites

Question

Hi All,I am looking for a guide which can help in deciding the required network bandwidth between the master and replica sites.Has anyone gone through such guide?Thanks,~Amit

grocha · Answer

I recently configured 4 replica sites for a customer, PTC's documentation on replication is not so deep and It was such a pain to achieve acceptable rate of success of the replication process, I didnt found any guide talking about bandwidth, but found out some hidden preferences and apache/tomcat/database tweaks that with moderate thinkering will help you to achieve good replication (around 95% of success in each replication process) in any bandwidth.

In this particular customer, thay had very poor internet connection between the master and the replicas, once the replicas were located in remote construction sites with only radio technology for connection. I was having massive packet loss, had to tweak apache, tomcat and windchill regarding timeouts and after that had to create indexes to increase replication speeds.

One thing that looks like is not working yet is the "scheduled replication" process, in a regular replication process, if a document fails to replicate (due packet loss or anything) it will be labelled as failed and windchill would try to replicate it the next day again. That is not working for me, everyday I have to manually reset failed replication items through vault configuration UI.

Below is the info I've saved in my evernote account for future reference, it was copy pasted from different places so the information is not so well organized.

You are in luck cause some of the preferences bellow was so hidden even first level PTC customer support didnt know about it and they are not in knowledge base, at least it wasnt, I had to escalate the case some times to find those out, tooked me like 1 month to gather the info bellow.

I hope it helps you and that you doesn't have such pain I had.

best of luck!

Tomcat is not closing connections from remote Apache server in Windchill

Tomcat is not closing connections from remote Apache server in Windchill.
Netstat on the Windchill Server shows increasing numbers of ESTABLISHED connections with the Remote Apache server.
Netstat on the Apache server does not show the same number of connections.
Tomcat eventually runs out of available connections
There may be a firewall between Apache and Tomcat

Applies ToWindchill 10.0, 10.1CauseFirewall was preventing Tomcat from detecting Apache closing connections from its connection poolResolution

Apache in 10.0 uses mod_jk to route AJP requests to Tomcat
Mod_jk maintains a pool of connections between itself and the Tomcat server
If a connection has been unused for a period of time, mod_jk will close the connection.
If Tomcat cannot detect this closing of the connection it will leave its end of the connection open.
Tomcat needs to be configured to close its end of the connection as well after a period of time

InApache\conf\extras\workers.properties the value ofworker.tomcat<n>.connection_pool_timeoutspecifies how long mod_jk will keep an idle connection open in the connection pool.
The timeout is specific in seconds
The default value is 900

If there is a firewall between Apache and Tomcat then :
This value should be set to less than any connection timeouts set in the Firewall.
Apache also recommend thatworker.tomcat<n>.socket_keepalivebe set toOn.

To update the values in workers.properties, perform the following steps

EditApache\confg.properties
SetajpConnTtlto the value you want to set theconnection_pool_timeout to.
SetajpKeepalive=Onif you want to enable keepalive when there is a firewall.
From a Windchill shell, in the Apache directory run :
2. ant -f config.xml configureAJPWorkers

In Tomcat aconnectionTimeoutvalue has to be set in server.xml to allow Tomcat to close its connections if they remain open too long.
This timeout is specified in milli-seconds, not seconds
This timeout should be for the same amount of time as the connect_pool_timeout in Apache. It should not be lower.
For example, if connection_pool_timeout=900 then connectionTimeout=900000

To update the Tomcat connectionTimeout value perform the following steps

1. Make a backup ofWindchill\tomcat\conf\server.xml.default
2. EditWindchill\tomcat\conf\server.xml.default
3. Locate the following section

@@PRE_AJP_DECL@@
<connector port="@@AJP13_PORT@@" protocol="AJP/1.3" secure="@@AJP_IS_SECURE@@" @@ajp_address_conn_attr@@<br="/> tomcatAuthentication="false" enableLookups="false" maxPostSize="-1"
useBodyEncodingForURI="true" URIEncoding="UTF-8" backlog="@@AJP_BACKLOG@@"
maxThreads="@@AJP_MAX_THREADS@@" minSpareThreads="@@AJP_MIN_SPARE_THREADS@@" maxSpareThreads="@@AJP_MAX_SPARE_THREADS@@"/>
@@POST_AJP_DECL@@

4. Add theconnectionTimeoutvalue as necessary with the value in "s. For example :

@@PRE_AJP_DECL@@
<connector port="@@AJP13_PORT@@" protocol="AJP/1.3" secure="@@AJP_IS_SECURE@@" @@ajp_address_conn_attr@@<br="/> tomcatAuthentication="false" enableLookups="false" maxPostSize="-1"
useBodyEncodingForURI="true" URIEncoding="UTF-8" backlog="@@AJP_BACKLOG@@"
maxThreads="@@AJP_MAX_THREADS@@" minSpareThreads="@@AJP_MIN_SPARE_THREADS@@" maxSpareThreads="@@AJP_MAX_SPARE_THREADS@@"connectionTimeout="900000"/>
@@POST_AJP_DECL@@

5. Save the file
6. Stop Windchill
7. Remove theinstance-*folders and files underWindchill\tomcat\instances
8. Start Windchill

wt.properties Options to play with, values really depends on your actual bandwidth and stability of it, I still doesnt have a perfect combination of values for this preferences, it really is a try and check results process.

CS67251

“A goal without a plan is just a wish.”

Sign up

Please use your PTC eSupport account.

Welcome to the PTC Community

Please use your PTC eSupport account.