Update a Global Variable

Using REST you can update global variables for one or multiple instances. It is supported only when you are using deployment with TIBCO Enterprise Administrator mode.

Here is a generic cURL example that updates global variable for one or multiple instances. 
curl -u <USER>:<PASSWORD> -X POST -H "Accept: application/json" -H "Content-Type: 
multipart/form-data" 
-v "<BROKER_URL>:<BROKER_PORT>/livecluster/rest/v1/sf/engines/<DAEMON_ID>/
 <ENGINE_INSTANCE>/archives" 
-F "archiveFile=@<ARCHIVE_FILE>" -F "COMMAND=saveglobalvariable" -F "INSTANCES=
  <INSTANCE_1,INSTANCE_2,...,INSTANCE_n>" 
-F "VARNAME=<VARNAME_IN_GLOBALVARIABLES_FILE>" -F "VARVALUE=<NEW_VARVALUE>"

Here,

INSTANCES : Identifies multiple instance names

VARNAME : The global variable name.

VARVALUE : The global variable value.