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Donald Baldwin - PeerSpot reviewer
Principal Enterprise Architect at Aurenav Sweden AB
Real User
Top 5
Handles a high volume of data, collects information from multiple sources, and is very stable
Pros and Cons
  • "The reporting aspect is good and it does what I need it to do."
  • "If you monitor too much, you can lose performance on your systems."

What is our primary use case?

In our organization, Splunk is used in our data centers.

We have integration services and other types of systems in our new IoT architecture. We're using it to capture information.

We use Splunk as an aggregator for monitoring information from different sources, however, for our protection suite, we're using Comodo.

It's designed to collect data from different points. It has a lot of integrations built into it and that's why we're using it.

We use it for our enterprise more - such as for messaging. There's a lot of stuff we do on our integration services layer that we use Splunk for. For security purposes, we're using Comodo. Therefore we're not using Splunk for security purposes. We're using it for monitoring what's happening at our integration services layer.

How has it helped my organization?

Splunk indicates when we've got problems popping up somewhere or we're not getting the flow we expected. If there's a problem, we have those flagged and we use it for logging.

What is most valuable?

Splunk handles a high volume of data that we have, and it does it really well.

For what we're using it for, we're happy with its functionality.

The reporting aspect is good and it does what I need it to do.

From an operational standpoint, it helps us on the operations side and it also shows where we're having issues.

It connects to a lot of stuff. We can collect information from a lot of sources.

What needs improvement?

The interface or maybe some settings need to be improved a bit. It cannot be perfect, however, the issues may be related to the configuration or setup.

If you monitor too much, you can lose performance on your systems. You have to be careful what you're monitoring. If you monitor everything, everything stops working. You can go overboard in monitoring. You have to plan your monitoring pretty carefully.

It could be easier for beginners. As it is, right now, You have to have a good understanding of the solution in order to use it properly.

That said, as the user, I'm at a higher level of management on the architecture side in dealing with resilience. My concerns are different from other user concerns. Also, most of our clients are using it way more than we're using it.

Buyer's Guide
Splunk Enterprise Security
April 2025
Learn what your peers think about Splunk Enterprise Security. Get advice and tips from experienced pros sharing their opinions. Updated: April 2025.
851,823 professionals have used our research since 2012.

For how long have I used the solution?

We've used the solution for more than a decade. It's been a long time. 

What do I think about the stability of the solution?

We haven't had any problems with stability. There are no bugs or glitches. It doesn't crash or freeze. It's reliable. 

What do I think about the scalability of the solution?

We've never had an issue with scalability. If a company needs to scale, it can.

The danger of Splunk is that it can get too big too quickly and you have to be very careful with what you want to be monitoring due to the fact that if you monitor too much, you can slow down things and you can hurt your performance on your system. We have to be very careful of what we're logging.

We have about 12 users on the solution right now.

We do not plan to increase usage in the future.

How are customer service and support?

We don't use technical support very much. We've been using it for so long, we generally understand it and do not require assistance.

Which solution did I use previously and why did I switch?

We used to use Splunk a lot more, however, we've moved more to Comodo right now. I'd say we've moved to Comodo from Splunk in a lot of areas.

On the security side, we use Comodo. Not all of our clients even have Comodo. A lot of them are using Splunk, however, a lot of them are using Splunk for enterprise operations and network operations items. Some of them are using security and a lot of them aren't. Splunk is offered as a security option now, however, originally, when you used it, it was to collect enterprise operations information and know-how your systems are running. 

How was the initial setup?

We've been using it for a long time, therefore, I don't even remember when we set it up or how it went. We do keep it updated and use the latest versions.

I only have one or two people doing maintenance on it.

What was our ROI?

ROI's a hard thing to pin down. We've had it for so long, it's part of our core operating infrastructure.

What's my experience with pricing, setup cost, and licensing?

Everything we do is either yearly or multi-year. I don't know if there is any additional cost to standard license fees.

What other advice do I have?

We use Splunk and we also sell and support it for our clients.

Normally our policy is to keep software updated to the latest version.

The main issue is that we do enterprise architecture and network and security operations. We recommend certain platforms to clients. We don't always sell Splunk directly to them due to the fact that, since we're being hired to help them make choices, we need to be neutral. In the cases where it doesn't make sense, we don't sell it. We just help clients make decisions.

I don't know which version of the solution we're using. I'm an architect; I'm not on the operations level. I'm not the one who actually uses it. Our operations use it. I get dashboard results and I do reports that are based on it, however, I'm not the one actually running it. We have a NOC and a SOC and others use it a lot more individually. They have a lot more interaction than I do. I'm getting reports out of it. Others are actually connecting to it, using it as a tool. I'm not a tool user. I'm an information user.

All Splunk is, is data collection and it can sort things out on a dashboard. However, a lot of what Splunk does is collect data and you have to decide what kind of information you're going to let it collect. When we're doing design operations we have to really pay attention to what we're doing, so we don't actually slow things down or impede things. The reason we use Splunk is we put a lot of data into it.

With Splunk, you need to really be careful about what you're monitoring and how you use it, to get keep the results working. It's a good tool if you know what you're doing and what you need to be logging. You need to be aware of what you're logging to ensure it isn't going to cause problems with your performance.

I wouldn't recommend it for somebody who's coming in new. Of the clients we have using it, I don't know if any of them don't have professional IT running it. It's important to really understand what's going on.

I'd rate the solution at an eight out of ten. In certain environments, it could be a bit complex. It's not something you could just drop into an organization, you need to be trained to use it. You need the experience to use it properly.

Disclosure: I am a real user, and this review is based on my own experience and opinions.
PeerSpot user
Senior Cyber Security Expert at a security firm with 11-50 employees
Real User
Great performance, easy to set up, and offers good speed
Pros and Cons
  • "The level of robustness on offer is very good."
  • "The complexity could be worked on so that it's even easier and faster."

What is our primary use case?

Typically, we use the solution for critical infrastructure companies. 

What is most valuable?

The speed is a very valuable aspect of the solution. 

The way Splunk handles low data and low-rate costs are great.

The level of robustness on offer is very good. 

The initial setup is very straightforward. 

We have found that the solution offers good integrations with other products.

Overall, the solution works very well.

What needs improvement?

The complexity could be worked on so that it's even easier and faster. However, I understand that, if some complexity was removed, there might be slightly more limitations.

Occasionally there are data sizing and data-related issues that need to be overcome.

For how long have I used the solution?

I've been using the solution for a couple of years.

What do I think about the stability of the solution?

The performance is very good. It's something that customers are always looking for. The product offers good stability. There are no bugs or glitches and it doesn't crash or freeze. It's reliable. 

What do I think about the scalability of the solution?

We have about five to ten partners that use Splunk.

Which solution did I use previously and why did I switch?

I'm a fan of QRadar. I use them as well.

How was the initial setup?

The initial setup is very straightforward. It's not overly complex or difficult. A company shouldn't have any issues with the process. The deployment process doesn't take too long. You can manage it with fewer people and smaller teams. This is especially true if it isn't the critical infrastructure that you are working with. 

For deployment and maintenance, you only need two to three people. That can include one manager and two professionals. Since Splunk is easier to handle, more people can join in on the client-side.

What's my experience with pricing, setup cost, and licensing?

We also use QRadar, and we make more money with QRadar than with Splunk as we can make bigger projects happen. However, we find that with Splunk, while we don't make as much money on each project, we can do more of them.

What other advice do I have?

I'd rate the solution at an eight out of ten.

Which deployment model are you using for this solution?

Public Cloud
Disclosure: My company has a business relationship with this vendor other than being a customer: Partner
PeerSpot user
Buyer's Guide
Splunk Enterprise Security
April 2025
Learn what your peers think about Splunk Enterprise Security. Get advice and tips from experienced pros sharing their opinions. Updated: April 2025.
851,823 professionals have used our research since 2012.
reviewer1630161 - PeerSpot reviewer
Founder at a marketing services firm with 11-50 employees
Real User
Easy to deploy and relatively simple learning curve; could be more user friendly
Pros and Cons
  • "Easy to deploy and simple to use."
  • "Could be more user friendly."

What is our primary use case?

We're using the solution to try to build a virtual network and put Splunk inside it and do some kind of transcentralization with a log server. Our aim is to track connections, network traffic and some personal databases. I'm the founder of the company and we are customers of Splunk.

What is most valuable?

Splunk can quickly be deployed and it's not difficult to learn the solution. 

What needs improvement?

The solution could be more user friendly and it's difficult to know at this stage whether our requirements will be met by the solution. 

For how long have I used the solution?

I've been using this solution for a couple of months. 

What do I think about the stability of the solution?

The solution is stable. 

What do I think about the scalability of the solution?

Scalability is good with Splunk. 

How was the initial setup?

The initial setup doesn't take much time especially if there's good bandwidth. In a small company deployment might take a month or two. If you have 100 devices then a technical team of three should be sufficient. They would need to be able to deal with log analysis, forensics and have general knowledge about admin systems. In time, we would expect to have thousands of users. 

What's my experience with pricing, setup cost, and licensing?

I think Splunk is expensive compared to other tools at the purchase stage. It's possible that if we can keep control of the costs involved down the track, it won't be so bad.

Which other solutions did I evaluate?

We studied four or five tools including Logrhythm and Exabeam. We went with Splunk for now and will see how that goes.

What other advice do I have?

I think this is a good solution and rate it a seven out of 10. 

Which deployment model are you using for this solution?

On-premises
Disclosure: I am a real user, and this review is based on my own experience and opinions.
PeerSpot user
reviewer1521537 - PeerSpot reviewer
Consultant at a financial services firm with 5,001-10,000 employees
Real User
Good scalability, dashboards, and alarms, but should have a default dashboard for a firewall and better knowledge base
Pros and Cons
  • "Its dashboard is valuable. If you have a good knowledge of how to create a dashboard, you can create any dashboard related to cybersecurity. If fine-tuned, the alarms that are triggered for instant review are also very valuable and useful."
  • "Splunk is query-based, which is not the case with most cybersecurity tools. It is based on search queries and can be difficult to use. It would be good if they can make it easier to understand how to create search queries. They can improve the knowledge base for better understanding. To create your dashboard, you need to have a search query. We have multiple firewalls in our company, and we need a dashboard for them. It would be helpful if a default firewall dashboard is included in Splunk to make monitoring easier. If a dashboard is available for a security device, the operation part will be more efficient. We won't have to follow a manual process for this."

What is our primary use case?

We are using Splunk for cybersecurity operations.

What is most valuable?

Its dashboard is valuable. If you have a good knowledge of how to create a dashboard, you can create any dashboard related to cybersecurity. If fine-tuned, the alarms that are triggered for instant review are also very valuable and useful.

What needs improvement?

Splunk is query-based, which is not the case with most cybersecurity tools. It is based on search queries and can be difficult to use. It would be good if they can make it easier to understand how to create search queries. They can improve the knowledge base for better understanding.

To create your dashboard, you need to have a search query. We have multiple firewalls in our company, and we need a dashboard for them. It would be helpful if a default firewall dashboard is included in Splunk to make monitoring easier. If a dashboard is available for a security device, the operation part will be more efficient. We won't have to follow a manual process for this.

For how long have I used the solution?

I have been using this solution for eight months.

What do I think about the stability of the solution?

In terms of operations, it is stable, but if you don't have a proper configuration and sizing, there could be many issues. It could be more efficient on the storage part. We are still in the deployment stage to be able to say that for sure.

What do I think about the scalability of the solution?

It is very scalable. Currently, we have around 50 users. We will increase its usage if more people need access.

How are customer service and technical support?

We have raised multiple tickets. Some of them are good, and some of them can be better. Overall, their technical support is okay.

Which solution did I use previously and why did I switch?

We didn't use any other solution.

How was the initial setup?

I didn't do the initial configuration. I take care of the operations part. One of our clients did it, and it is somehow complex, and it takes time. It also depends on your knowledge. If you don't have knowledge of Splunk, it is complex.

Which other solutions did I evaluate?

We are a partner of Splunk. So, we did not evaluate other solutions.

What other advice do I have?

I would rate Splunk a seven out of ten.

Which deployment model are you using for this solution?

On-premises
Disclosure: My company has a business relationship with this vendor other than being a customer: Partner
PeerSpot user
it_user782697 - PeerSpot reviewer
Security Operation Center Analyst at Sadad
Real User
User Behavior Analytics is key in detecting fraud and advanced persistent threats
Pros and Cons
  • "Splunk UBA is useful for fraud detection and for detection of APTs, advanced persistent threats."
  • "UBA, User Behavior Analytics, is a key feature."
  • "I think the machine learning should be emphasized. Now, it's really important to analyze Big Data, data mining. A SIEM solution, like Splunk, needs an improved data mining solution, artificial intelligence."

What is our primary use case?

Splunk is a SIEM, a Security Information and Event Management solution. It is used, for example, for monitoring security logs and security information in companies and organizations. It is also used for correlation, meaning making policies, for detecting/monitoring attacks, and the like; for monitoring security logs, security events, preventing hackers from attacking. It's really for business continuity.

How has it helped my organization?

For a long period of time we analyzed logs, traffic, something like tcpdump. Splunk UBA is useful for fraud detection and for detection of APTs, advanced persistent threats. It's really important for our business because I work a PSP, a payment service provider, e-payments.

What is most valuable?

UBA, User Behavior Analytics.

What needs improvement?

In the next release of Splunk, I think the machine learning should be emphasized. Now, it's really important to analyze Big Data, data mining. A SIEM solution, like Splunk, needs an improved data mining solution, artificial intelligence. Splunk would be the best if it improved these features.

What do I think about the stability of the solution?

It's stable and very safe. 

What do I think about the scalability of the solution?

Splunk's scalability is good for an enterprise situation. It's scalable in all situations.

How are customer service and technical support?

For us, technical support has been good. Splunk has good documentation and it is really easy to work with Splunk and the Splunk community.

Which solution did I use previously and why did I switch?

I used ELK. It was good. It is an open-source solution, but there is some complexity in configuring it, working with it.

In choosing a vendor I use industry reviews to find feedback from the community that works with the solution.

How was the initial setup?

The initial setup was straightforward.

Which other solutions did I evaluate?

There are a lot of solutions: IBM QRadar, Splunk, LogRhythm. Splunk was good for us because of the support, the documentation, the scalability, the stability. It gives us everything that we need in our business, everything necessary for helping us do our job.

What other advice do I have?

There are three top SIEM solutions in the world: Splunk, LogRhythm, IBM QRadar. I think Splunk is the best.

I would rate Splunk at eight out of 10. The vendor needs to work on this solution to make it better and better. I would recommend this solution but it depends on the situation, the country, the support from the vendor.

Disclosure: I am a real user, and this review is based on my own experience and opinions.
PeerSpot user
PeerSpot user
Security Engineer at Information Innovators Inc. (Triple-i)
Real User
Correlates logs throughout the enterprise for searching and use in investigations
Pros and Cons
  • "We primarily use it to correlate logs throughout the enterprise for both searching and use in investigations."
  • "It can be tough to get a hold of somebody in technical support depending on the complexity of the issue."
  • "The Enterprise Security app could be improved. We have had trouble with it working from the first day."

What is our primary use case?

We primarily use it to correlate logs throughout the enterprise for both searching and use in investigations.

How has it helped my organization?

We previously did not have a good centralized solution which could ingest just about any log type, which has been a plus.

What is most valuable?

The search application has been the most useful. We have also liked the reporting features and dashboard capabilities.

What needs improvement?

The Enterprise Security app could be improved. We have had trouble with it working from the first day.  

For how long have I used the solution?

More than five years.

What do I think about the stability of the solution?

Yes, there have been issues with the Enterprise Security application instance.  

What do I think about the scalability of the solution?

No issues.

How are customer service and technical support?

It has been a weak point, but has improved over the years. It can be tough to get a hold of somebody depending on the complexity of the issue.  

Which solution did I use previously and why did I switch?

Years ago, we did use another solution, but I am not sure it exists any longer. We have been using Splunk for many years.  

How was the initial setup?

We had professional services set it up, as it was quite complex.  

What about the implementation team?

Vendor implementation, and I would rate them as a seven out of 10.  

What was our ROI?

Excellent overall. 

What's my experience with pricing, setup cost, and licensing?

It can be expensive, especially the licensing costs. However, there is added value in what it can do, not just log aggregation.  

Which other solutions did I evaluate?

We evaluated Trustwave and QRadar.

What other advice do I have?

It is a great product overall. I would like to see improvements on the Enterprise Security app/SIEM functionality.  

Disclosure: I am a real user, and this review is based on my own experience and opinions.
PeerSpot user
PeerSpot user
Specialist Master, Cyber Risk at a tech vendor with 10,001+ employees
Real User
My clients have visibility into systems and activities that they never had before.
Pros and Cons
  • "Splunk gives my clients the ability to bring multiple, disparate types of data together, then correlate and report on them."
  • "The GUI can be improved. Splunk has always suffered from having a kind of goofy UI, it needs some updating."

How has it helped my organization?

Some of my clients had rudimentary home-grown security solutions that Splunk ES has completely replaced.

In these cases, the improvement was dramatic; they had visibility into systems and activities that they never had before.

In the case of clients who already had a SIEM solution, the change was more incremental. However, in my opinion, the Splunk ES solution is superior because it is so flexible. It can consolidate data from almost anything.

What is most valuable?

Splunk Enterprise Security is most valuable, my clients use it as a SIEM solution. Splunk gives them the ability to bring multiple, disparate types of data together, then correlate and report on them.

What needs improvement?

The GUI can be improved. Splunk has always suffered from having a kind of goofy UI, it needs some updating.

What do I think about the stability of the solution?

There were no stability issues. It is one of the most stable systems that I have worked with.

What do I think about the scalability of the solution?

As of now, no scalability issues were experienced. Splunk is highly scalable, so don’t anticipate that. However, scaling can get very expensive with their pricing model.

How are customer service and technical support?

Technical support is excellent! It is of top notch level. The customer support folks really know their stuff, the turnaround is fast.

Which solution did I use previously and why did I switch?

Previously, we were using HPE ArcSight.

How was the initial setup?

That’s a hard one. The initial setup is easy but making it actually work is complex. However, the complexity is something that just comes with all top SIEM tools. Very few companies have exactly the same data and issues, so a great deal of data onboarding and normalization are always required.

Which other solutions did I evaluate?

We evaluated HPE ArcSight.

What other advice do I have?

Plan your implementation carefully. Be sure you have someone to implement it, someone who knows what he is doing. Splunk’s inherent flexibility is a great thing, but it also provides an opportunity to really mess things up.

Disclosure: My company has a business relationship with this vendor other than being a customer: We are an alliance partner.
PeerSpot user
PeerSpot user
Manager, Enterprise Risk Consulting at a tech company with 1,001-5,000 employees
Real User
Innovative tool but it needs to be improved for day to day use.

SIEM posts have grown in number at Infosecnirvana, but the requests to write about more products keep coming in. One of the oft asked about product is Splunk Enterprise. We have posted on HP ArcSight, IBM QRadar and McAfee Nitro SIEM. However, readers have been asking us repeatedly to write on Splunk.

So here it is finally after being in the works for a long time.

Introduction:

In 2003, One of the most interesting products rolled out and vowed to simplify Log management once and for all (and it did!!!) - Splunk. Their motto was simple – Throw logs at me and I will provide a web based console to search through it intuitively. Interestingly they are one of the few companies that have not been acquired, in spite of being a very innovative product. So let’s see what makes Splunk tick.

Architecture:

As always, a product is as good as its architecture. It has to be solid both internally as well as externally (meaning solution deployment, integration, ease of use, compatibility etc.).

  • Internal Architecture: Under the hood Splunk has two main services – The Splunk Daemon that is written in C++ used for data collection, indexing, search etc. and the The Splunk Web Services that is a web application written using a combination of Python, AJAX, XML, XSLT etc . which provides the super intuitive graphical UI. Splunk also provides API access using REST and it can integrate with any web framework needed. Splunk is one of the few products that still use C++ and Python instead of the clunky Java and its cousins. This provides the edge to Splunk when processing large data volumes thrown at it.
  • Data Architecture: Splunk is a unique search engine like “data architecture”. In fact, some of the early development was based on the same concept of the path breaking GFS (Google file system) which provided a lot of direction and research into flat file storage, indexing and free text search capabilities with unmatched speed when compared to a relational DB. Splunk went on to master the distributed file system architecture and built their own proprietary data store which powers Splunk Enterprise today.
  • Deployment Architecture: The deployment of Splunk is based on true Big Data Architecture – Slave and Master, where the Slaves are the Search Indexers and the Master is a search head. Of course you can have both the nodes in the same Physical server, but in a true distributed architecture, you need a master and a slave. Read more at Big Data – What you need to know? to understand better on what Big Data is and how to try your hand at it.
  • Typical Setup: Lets look at a typical architecture deployment of Splunk in distributed mode.

Splunk_img4
As you can see, there are three distinct components of this architecture and they are as follows:

  1. Log collectors or Splunk Log Forwarders are installed closer to the source and forward all the logs to Splunk Indexers. This is similar to the Log Collectors in SIEM. They are not great, but are decent enough to get the job done.
  2. The Splunk indexers typically run only the Splunk Daemon service, that receives the data and indexes it based on a pre-defined Syntax (this is akin to parsers but lot more simpler and faster to process). This is then sent to the Splunk data store. Each data store has a set of indexes based on the amount of logs received. The data store can then be configured for retention, hot or cold or warm standby etc. etc. In big data terminology, these are the slave nodes.
  3. These indexers then use a process called as “Summarizer” or in big data terms – “Map reduce” to create a summary index of all the indexes available.
  4. Splunk Search head, which serves as the single console to search across all data stores has the “summary index” to know which Indexer (slave) node to query and what index to query. Now this is where the scalable search power of Splunk comes from. This is the master node in big data world.

What’s good about Splunk?

  • Search, Search & Search: Splunk is arguably the best search engine for logs out there. We have started looking at ELK, Hadoop and other big data search engines but for the moment, Splunk rules the roost. The Splunk Search Processing Language (SPL) is the reason behind this power. The search can be done historically (on indexed data) or in real time (data before indexing) and this is as good as Log search can get. None of the SIEM products can come close to the search power of Splunk. In other words, Splunk is to search Log Data and SIEM is to search Event Data.
  • Fully customizable as far as searching capabilities is concerned, Splunk lets us add scripts to search queries, provides field extraction capabilities for custom logs, provides API, SDK and Web framework support to achieve all that you would need for Log management, Investigations, Reporting and alerting.
  • Web Interface: Even though UI is a subjective benefit, Splunk has one of the most pleasing interfaces we have seen for log management tools. It really is super easy and intuitive to use. It has great visualization capabilities, dashboards, app widgets and what not. It really puts the cool factor in a rather dull log analysis experience.
  • No Parsing: Basically, Splunk is an “All you can eat” for logs. Splunk follows a “store now, parse later” approach which takes care of receiving any logs thrown at it without any parsing or support issues. If it is a known log type, the indexes are added and updated appropriately. If it is not a known type, still the logs are stored and indexed to be searchable for later. You can then use Field Extractions and build custom field parsings. This is one of the killer differentiators compared to traditional SIEM products as Splunk is a lot more forgiving and agnostic in log collection and storage and does not require specialized connectors or collectors to do the job. This makes it a great log management product.
  • Splunk Apps help in building on top of the Search head to provide parsing, visualizations, reporting, metrics, saved searching and alerting and even SIEM-like capabilities. This, in my opinion is the power of Splunk compared to the other products in the market. They have an App Store for Splunk Apps. Cool isn’t it? These apps not only are written by product vendors, but also by User community.
  • Scalability: Splunk is a true big data architecture. It can scale with addition of Indexers and search heads. Ratio of Search Heads to Indexers is at a good 1:6. This means that if you have 1 search head, you can have 6 search indexers. This is very attractive when compared to other SIEM solutions in the market when it comes to scaling at the log management layer.

What’s bad?

  • Not a SIEM: Splunk is not your traditional SIEM. Let me clarify further. SIEM has several things in it that assists in performing security event management, monitoring, operations and workflow. In short the keyword for SIEM is “Operational Security Management”. Now the question is – Can Splunk be an SIEM? The simple answer is YES, however the real answer lies in how much customisation and how much product expertise you have in store to make it a SIEM product.
  • Poor Correlation: Splunk does not do any correlation as it is not designed to do that. However, it can be used to correlate events using the Splunk search language. You can do manual correlation using piped searches, lookup tables, scripted searches etc. but again you need to be familiar with the language. You can also automate it by scheduled and real time search triggers. However, nothing is out of the box. Anton blogs about Splunk Correlation being far superior to ArcSight (which btw is the best correlation engine we have worked with) but honestly, we don’t have real life implementation experience to justify that.
  • SIEM App: Splunk has an enterprise SIEM app that aids in SIEM-like functions. But it is definitely not a replacement killer for SIEM product. It is very basic and and does not do much out of the box.
  • No Aggregation: The logs being sent to Splunk are received as is and sent to the data store. It is not aggregated. This while is a good thing for log collection and search performance, it is not good for underlying storage sizing. SIEM solutions have this capability but Splunk does not. This in turn affects the scalability aspect.
  • Poor Compression: Many SIEM products have a compression ratio of 10:1. However for Splunk, we have consistently seen the ratio to be around 4:1. This while good for smaller log volumes, is very poor for larger volumes. The main reason for this is that the Indexes take a lot of storage compared to the raw logs. While they aid in greater search capabilities, they increase underlying storage and maintenance cost.
  • Scalability: Even though, Scalability is one of the benefits of using Splunk for Log management, there is a downside to it too. Add to it the lack of aggregation, compression etc. and you can see how it impacts Scale. For example, Every indexer can handle only 100 – 150 GB/day on a good server hardware. In spite of what people might say about Splunk sizing and performance tuning, from years of personal use and experience, we can safely say that for standard enterprise hardware, this limit is as good as it gets. So assume you are looking at 1 TB/day. You would need 8 indexer servers and 2 search head servers for Splunk. However, if you were to take ArcSight or QRadar, you could do the same on two appliances with compression enabled (10:1 ratio of compression). This from a management perspective leads to larger foot print for Splunk than other SIEM products.
  • Price: Contrary to popular belief, Splunk can get very expensive very fast. For all the reasons mentioned above, Splunk can get very expensive compared to other SIEM vendors to do large data collection as well as SIEM functionality. In a word – Be Cautious!!!

Conclusion: In our opinion, Splunk is one of the most innovative log management tools out there. But as a SIEM, to use in day to day security management, monitoring, ticketing etc. it has a lot of catching up to do. The ideal scenario will be to use Splunk in the log management layer and use any market leading SIEM in the correlation, workflow and operational management layer. We have seen several successful implementations where Splunk serves as the log management tool and ArcSight or QRadar serves as the Correlation engine. Best of both worlds!!!

Disclosure: I am a real user, and this review is based on my own experience and opinions.
PeerSpot user
Alireza Ghahrood - PeerSpot reviewer
Alireza GhahroodConsultant & Instructor -Cyber Security,GovernanceRIskCompliance (CISO as a Services) at Independent
Top 10Real User

thank you for a good review.

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Buyer's Guide
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Updated: April 2025
Buyer's Guide
Download our free Splunk Enterprise Security Report and get advice and tips from experienced pros sharing their opinions.