Wrapping up our Software vs. Appliance series, I want to remind the audience this series was prompted by my desire to spotlight the FUD in Database Activity Monitoring sales processes. I have mentioned data collection as one of the topics Data collection matters. As much as we would like to say the deployment architecture is paramount for performance and effectiveness, data collection is crucial too, and we need to cover a couple of the competitive topics that get lumped into bake-offs.

One of the most common marketing statements for DAM is, “We do not require agents.” This statement is technically correct, but it’s (deliberately) completely misleading. Let’s delve into the data collection issues that impact the Appliance vs. Software debate:

  • Yes, We Have No Agents: No database activity monitor solution requires an agent. You’ll hear this from all of the vendors because they have to say that to address the competitive ‘poison pill’ left by the previous vendor. All but one DAM product can collect SQL and events without an agent. But the statement “We don’t require an agent” is just marketing. In practice all DAM products – software, hardware, and virtual – use agents. It’s just a fact. They do this because agents, of one form or another, are the only reliable way to make sure you get all important events. It’s how you get the whole picture and capture the activity you need for security and compliance. Nobody serious about compliance and/or security skips installing an agent on the target database.
  • No Database Impact: So every DAM vendor has an agent, and you will use yours. It may collect SQL from the network stack by embedding into the OS; or by scanning memory; or by collecting trace, audit, or transaction logs. No vendor can credibly claim they have no impact on the target database. If they say this, they’re referring to the inadequate agent-less data collection option you don’t use. Sure, the vendor can provide a pure network traffic collection option to monitor for most external threats, but that model fails to collect critical events on the database platform.

Don’t get me wrong – network capture is great for detecting a subset of security specific events, and it’s even preferable for your less-critical databases, but network scanning fails to satisfy compliance requirements. Agent-less deployments are common, but for cases where the database is a lower priority. It’s for those times you want some security controls, but it’s not worth the effort to enforce every policy all the time.

  • Complete SQL Activity: DAM is focused on collection of database events. Agents that collect from the network protocol stack outside the database, or directly from the network, focus on raw unprocessed SQL statements in transit, before they get to the database. For many customers just getting the SQL statement is enough, but for most the result of the SQL statement is just as important. The number of rows returned, or whether the query failed, is essential information. Many network collectors do a good job of query collection, but poor result collection. In some cases they capture only the result code, unreliably – I have seen capture rates as low as 30% in live customer environments. For operations management and forensic security audits this is unacceptable, so you’ll need to verify during vendor review.
  • Database Audit vs. Activity Audit: This is a personal pet peeve, something that bothers most DAM customers once they are aware of it. If your agents collects data from outside the database, you are auditing activity. If you collect data from inside the database you are auditing the database. It’s that simple. And this is a very important distinction for compliance, where you may need to know database state. It is considerably more difficult to collect from database memory, traces, transaction logs, and audit logs. Using these data sources has more performance impact – anywhere from a bit to much more impact than activity auditing, depending upon the database and the agent configuration. Worse, database auditing doesn’t always pick up the raw SQL statements. But these data sources are used because they give provide insight to the state of the database and transactions – multiple statements logically grouped together – that activity monitoring handles less well.

Every DAM platform must address the same fundamental data collection issues, and no one is immune. There is no single ‘best’ method – every different option imposes its own tradeoffs. In the best case, your vendor provides multiple data collection options for you to choose from, and you can select the best fit for each deployment.