IBM Log Analysis with LogDNA is well suited if you are using other IBM cloud product ecosystems. It's very mature and supports HIPAA-compliant configurations if you need to store PI/PHI data. We particularly use it for audit requirements but understand the limitation with the retention period is for 30 days only. Also you need to configure if your IBM cloud service doesn't have any log collection or report tool. Log collection agents are widely supported for most of infrastructure in cloud.
Logstash is a must in an ELK stack, which I am sure is going to be the #1 case. At any point when you have several sources, Logstash can be the common point to aggregate, and categorize those data. Then send this new data to its destination. Very handy. It is free and open source. It may not be appropriate to analyze data-sets dependent on each other but from a different data source. Reason being Logstash works on data at hand, and not wait for other data to arrive. It would be unwise for Logstashh to handle complicated, long-running transformations because this is injected and ejected. The faster you do it, the safer.
Memory: Logstash is a HOG, if you are deploying it on commodity (i.e. cheap and old) hardware: You will need at least 2GB, just for Logstash. So don't expect to run your entire ELK stack on one AMD Athlon machine.
Overlap: Logstash fills in an area of the ELK stack that makes the most sense: as a log file transformer / shipper. However, if you start breaking that stack, with the addition of other components- you start seeing where features of Logstash may be implemented or solved in the additional components much easier (or better, or to a higher degree of resolution)
More Overlap: Since my team employs Syslog-ng extensively- Logstash can sometimes get in the way (and this may be a problem for DevOps stacks overall): You can configure Syslog to record certain information from a source, filter that data, and even export that data in a particular format. Logstash will pick that data up, and then parse it. However, if you don't keep your Syslog-ng configuration files, and your Logstash configuration files in sync, your results will not be what you expected, and this will translate into (sometimes) hours/days of work, hunting down a line item in a configuration file.
As I said earlier, for a production-grade OpenStack Telco cloud, Logstash brings high value in flexibility, compliance, and troubleshooting efficiency. However, this brings a higher infra & ops cost on resources, but that is not a problem in big datacenters because there is no resource crunch in terms of servers or CPU/RAM
If you use other IBM product ecosystems, IBM Log Analysis with LogDNA is the obvious choice, as it supports seamless integration and better access control with IBM cloud access group setups. IBM Log Analysis with LogDNA was flexible and has wide support for various infrastructure implementations and is also controlled by the same IAM access setup. It can be configured for any IBM cloud services or platform logs or for infrastructure by installing the agent.
MongoDB and Azure SQL Database are just that: Databases, and they allow you to pipe data into a database, which means that alot of the log filtering becomes a simple exercise of querying information from a DBMS. However, LogStash was chosen for it's ease of integration into our choice of using ELK Elasticsearch is an obvious inclusion: Using Logstash with it's native DevOps stack its really rational
Most of IBM cloud services support easier integration for log analysis.
We are able to achieve compliance with various audit log reports, which improves governance and control over various cloud resources we have.
Also IBM Log Analysis with LogDNA helps in troubleshooting and analysis for application logs in real time. This helps with improved issue resolution timings.
It is very difficult to give any figures on ROI, as it depends on many factors, and in a Telcocloud environment, it is much complex to find out; however, I would give some points below on ROI
ROI based on flexibility is very high, as it reduces the time to find RCA
ROI based on integration is very high because it supports multi-vendor environments, avoiding vendor lock-in & works across multi-cloud setups
ROI on resource consumption is less because Logstash in 2-3 times more resource-intensive as compared to its lightweight alternatives resulting in latency
