Create and Add a new Pega 7.2nstance
Hi,
I'm a newbie on Pega :)
I've installed Pega Platform 7.2.1 on a Linux server with Tomcat.
Right now, I need to create a new Pega instance on another server (same as the first) for cluster mode. Can you tell me if I'm must follow only steps on chapter "Setting up the application server" (Pega721_Install_Tomcat_PostgreSQL.pdf), which means:
1- configure Tomcat
2- deploy applications archives
After that, I need to add this new node by using SMA and adds this Pega instance on the Load Balancer and its done!
Looks so easy ;)
Thanks for your help
***Updated by moderator: Lochan to add Categories***
Capgemini
FR
Hi WaikeiDwok,
Thanks for your answer!
I've got another question about high availibility: I've found in the document Pega721_HighAvailabilityGuide.pdf (in attachment) these lines p28:
With crash recovery enabled, the Pega 7 Platform saves the structure of the user interface and relevant work metadata to the database on
user interface events.
But when you see the chapter "Server crash recovery" (p28), they recommend to use shared storage :
Two settings are required to enable Pega 7 Platform server crash recovery:
- storage/class/passivation/rootpath must be set to shared storage that is available to all servers in the cluster.
- session/ha/crash/RecordWorkInProgress=true indicates to the Pega 7 Platform that user interface metadata will be stored to the share file system.
Do you know why we need to use shared storage instead on the database ? Thanks
NB: have you done other settings for the high availability working well (it's the first Pega platform I build and I don't have any experience on this technology) ? Thanks
Pegasystems Inc.
US
Good question, in fact, for 7.2.1, if HA is enabled (as defined by the prconfig setting ' */
session/ha/Enabled' with the value of true) - the default shared storage is database and that is recommended (in general having better performance).
Pegasystems Inc.
US
i think session/ha/crash/RecordWorkInProgress=true is specific to the user interfact metadata (current tab, work object id, harness information etc), which is stored in the file system.
Capgemini
FR
Hi,
Thanks WaikeiKwok and KevinZheng
There are two kinds of shared storage:
- database (default when ha is enabled)
- FS
What I understand it's that for better recovery when crash, we must activate session/ha/crash/RecordWorkInProgress=true and for that, we need to have a shared storage FS, no?
Thanks
Pegasystems Inc.
US
Try refer to page 19 under https://docs-previous.pega.com/pega-721-high-availability-administration-guide for the setting session/ha/Enabled.
Pegasystems Inc.
US
You would need to add it in, I don't believe it is there by default.
In prconfig you would add:
<env name="session/ha/Enabled" value="true" />
Or, if you make a DSS instead...
Owning RuleSet: Pega-Engine
Purpose: prconfig/session/ha/Enabled/default
Value: true
Capgemini
FR
Hi,
Thanks but I don't really understand because you can find in p19 on Pega721_HighAvailabilityGuide.pdf document:
Configuring high availability landing page visibility
You can display or hide high availability landing pages by adjusting the following prconfig setting.
session/ha/Enabled
l Value Type — Boolean
l Value — true or false
l Functionality — Switch to turn on or off the landing page user interface (UI)
l High availability aspect
l When the Pega 7 Platform is installed, this is set to true.
l Administrators must choose to use landing pages, AES, a NOC, SMA, or MBeans to manage
high availability
Pega 7.2.1 High Availability Administration User Guide 19
Quiesce
l Landing pages:
l Are not recommended due to latency of system pulse communication
l Are useful for testing purposes or Pega 7 Platform installations that do not have
Network Operations Centers
l Can be set through DASS — Yes
l Example: <env name="session/ha/Enabled" value="true" />
Looks like this setting only use for HA landing page visibility, no?
Thanks
Pegasystems Inc.
US
Sorry, I was answering your question "But where can I find the setting session/ha/Enabled ?" It is not present in prconfig.xml by default, but appearently it defaults to true.
What exactly are you looking for at this time?
Capgemini
FR
Thanks NickLoving
My question is on session/ha/enabled setting: is it used for enable high availability or, like say in HA document: only to turn on or off the landing page user interface (UI) ?
Thanks
Pegasystems Inc.
US
As far as I can tell, that setting is only used to turn the landing page on and off for users with the correct role to see them.
Some testing I did showed that turning this off in prconfig.xml made no change. It needs to be a DSS with the following values:
Owning RuleSet: Pega-Engine
Purpose: session/ha/Enabled
Value: false