Tag: OMS

Using Custom Log Search Alerts Based on Metric Measurement for Event Based Logs

In Azure Monitor we can create two type of alerts for Log Analytics:

Near real-time metric alerts are scoped to specific performance counter and heartbeat events but with Custom Log Search Alerts you can alert on any log in Log Analytics. With Custom Log Search Alerts the alert logic have two types:

  • Number of results
  • Metric Measurement

In a typical scenario you will use Number of results for logs and events and metric measurement for performance/metric logs. That wouldn’t be a problem if the way the alerts are fired distinguish quite a lot between those. For example in metric measurement you aggregate/summarize results and you alert based on the value from the aggregation/summarization. On top of that different alert instance is fired on each summarized record. In number of results you do not summarize/aggregate and alerts are fired based on the count of the records. For example on 10 records you will get only one alert instead of 10. If you are like me this is a problem as you want to get separate alert instance for your events just like metric measurement alerts.
In this blog post I will show you how to overcome this problem with workaround from the powerful Log Analytics query language.

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Configure OMS Linux Agent Heartbeat Interval

As you know both OMS Linux and Windows agent send heartbeat events and they are free of charge. The problem is that the interval of these heartbeat events is different for both operating systems. For Windows it is every 1 minute and for Linux is every 5 minutes. I do not know exactly the reason for this decision but I prefer that all my servers report at the same interval. The beautiful thing with the OMS Linux agent that is extendable and configurable. So this blog post will focus on how you can easily change the heartbeat interval on OMS Linux agent to 1 minute.

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Monitoring Windows Services States with Log Analytics

Monitoring Windows Services States is one of the most common requests that I’ve seen on forums, groups and blog posts. My fellow MVP and OMS expert Stefan Roth wrote a similar blog post titled OMS – Monitor Windows Services / Processes. I would suggest to check it out as well. The approach I will show is somehow already cover in official article that demonstrates custom fields in Log Analytics. The difference is that we now have the new rich Log Analytics search syntax so we do not need  custom fields anymore. This approach also is different from Stefan’s as his one covers wider topic with monitoring processes by using performance counters. In this approach we will use windows events which Stefan mentions that is not reliable but he was referring to specific Event Id which I also agree it is not reliable. In the next steps I will use another Event Id that is reliable 100%. The advantage of using windows events for monitoring windows services states are:

  • Only windows events are gathered which results in less data uploaded compared to performance data

  • You do not have to add performance counter for each process, you just need to add only one event log to monitor all services

  • The services are shown with their actual name that is used in services.msc or Get-Service cmdlet.

  • We have the actual state of the service when it happened

Some of the disadvantages of this method are:

  • Until the service is started or stopped it will take at least 5 minutes until the data appears in Log Analytics

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Tips and Tricks of Setting up Azure Security Center

Since Ignite 2017 Security & Compliance offering is now part of Azure Service Center service. Because of that some of the controls of that offering are moved to ASC but still the integration is not complete at least to me. With this blog post I will focus on two of the ASC settings that you should set up when you start with ASC – Changing to another Log Analytics workspace and Security Events level (filtering). Continue reading “Tips and Tricks of Setting up Azure Security Center” →

Mitigate speculative execution side-channel vulnerabilities

Seems the new year bring us some bad surprises in terms of security. There has been some rumors and now turned out to be truth that certain processors are vulnerable to certain attacks. Yes processors. That means that affects a wide variety of Operating Systems. As Microsoft puts it:

Microsoft is aware of a new publicly disclosed class of vulnerabilities referred to as “speculative execution side-channel attacks” that affect many modern processors and operating systems including Intel, AMD, and ARM. Note: this issue will affect other systems such as Android, Chrome, iOS, MacOS, so we advise customers to seek out guidance from those vendors.

Source: ADV180002 | Guidance to mitigate speculative execution side-channel vulnerabilities

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