Can you be more specific? If you search this site for 'threat detection' you get lots of different technologies: MDR, XDR, UEBA, IDPS, etc. I have used a threat intelligence services, as well as UEBA, and 'threat hunting' services with MDR as well as traditional IPS/IDS and other layered services. Each one detects threats differently - by external intelligence, by network activity, by host activity.
Off the cuff, I would suggest Nagios.
Unfortunately, the OSE doesn't provide any support though it does offer a limited support agreement. So, if you have a good Unix or Linux administrator who can supply the needed amount of time to configure everything then it's free minus the time they would spend (which is going to be significant initially) out of the box. It does give you basic monitoring of system-level stuff, disks, processes and users.
Advanced configuration is time-consuming for whoever is tasked, and unfortunately, some false positives will be experienced initially. I set up the basics for a customer once.
If you have a little money I'd suggest the Enterprise version of the product: thousand of plugins, and the console has functionality that the OSE doesn't include which will make the life of whoever is responsible a little easier.
If you have a small enterprise then that's a good sensibly affordable solution.
There's a lot of other more granular products that can be configured to stand up and dance if you hire experts to provide the care and feeding.
We have Tibco RV deployed for messaging both request reply and certified delivery in a highly distributed environment.
This is a very old 2004 deployment and Tibco itself has now moved away from RV.
What could be a good alternative for Bank financial transactions like messages movement with security reliability, no loss and guaranteed delivery in a distributed environment?
Yes, RV is very old now and as a company we now sell TIBCO Messaging under which our customers can use and be supported with either FTL, EMS, Apache Kafka, Pulsar or Mosquito. We do not believe that a single 'one-size-fits-all' approach is good for customers hence the reason to give our customers the best flexibility to choose a messaging distribution solution based on their needs and allow them even greater flexibility to adopt different patterns throughout their product's lifecycle all backed by enterprise support from a company that's been in the messaging industry for nearly 40 years.