Introduction to Monitoring Analysis Services

Effective monitoring of Microsoft SQL Server Analysis Services (SSAS) is crucial for maintaining performance, ensuring availability, and troubleshooting issues. This section provides an overview of the key areas and tools you should leverage to monitor your SSAS environment.

Why Monitor SSAS?

Monitoring SSAS helps you to:

Proactively identify performance bottlenecks: Detect slow queries, high CPU usage, or memory pressure before they impact users.
Ensure service availability: Track server status and detect failures or unexpected restarts.
Diagnose and resolve issues: Gather detailed information about errors and resource consumption to pinpoint the root cause of problems.
Optimize resource utilization: Understand how your SSAS instances are using hardware resources and identify opportunities for tuning.
Capacity planning: Track trends in usage and performance to anticipate future resource needs.

Key Areas to Monitor

When monitoring Analysis Services, focus on the following critical areas:

Performance Metrics

These metrics provide insights into how efficiently your SSAS instances are processing queries and managing data:

Query Latency: The time it takes for queries to complete. High latency indicates potential issues with query design, data model, or server resources.
CPU Utilization: High CPU usage can point to complex queries, inefficient processing, or insufficient hardware.
Memory Usage: Monitor both committed memory and available memory. Excessive memory consumption can lead to page-outs, severely impacting performance.
Disk I/O: Monitor read and write operations to disk. Slow disk performance can be a significant bottleneck for large datasets.
Cache Hit Ratio: A good cache hit ratio indicates that SSAS is effectively using its memory cache to serve queries quickly.

Service Availability and Health

Ensuring your SSAS service is running and accessible is paramount:

Service Status: Confirm that the Analysis Services service is running.
Error Logs: Regularly review the SQL Server and SSAS error logs for any critical errors or warnings.
Connection Attempts: Monitor successful and failed connection attempts to identify potential security or network issues.

Query Activity

Understanding what queries are being run and how they perform is vital:

Long-Running Queries: Identify queries that take an unusually long time to execute.
Resource-Intensive Queries: Pinpoint queries that consume significant CPU or memory.
Query Throughput: Track the number of queries processed over time.

Tools for Monitoring SSAS

Microsoft provides several tools and techniques to help you monitor your SSAS environment:

SQL Server Management Studio (SSMS)

SSMS offers a graphical interface for connecting to and managing SSAS instances. You can:

View server properties and status.
Monitor active sessions and process information.
Run DMVs (Dynamic Management Views) for detailed insights.

Performance Monitor (PerfMon)

PerfMon allows you to collect and visualize performance data using SSAS-specific performance counters. Key counters include:

\Analysis Services: Server\Calculate]
\Analysis Services: Server\Queries]
\Analysis Services: Memory\Cache Hit Ratio]
\Analysis Services: Cache\Memory Cache]

Tip: Create custom performance counter logs in PerfMon to track these metrics over time and set up alerts for threshold breaches.

Dynamic Management Views (DMVs)

DMVs provide real-time operational information about the SSAS instance. Some commonly used DMVs include:

$System.DISCOVER_PERFORMANCE_COUNTERS: Retrieves performance counter values.
$System.DISCOVER_CONNECTIONS: Shows active client connections.
$System.DISCOVER_SESSIONS: Lists active user sessions.
$System.DISCOVER_TRANSACTIONS: Displays information about current transactions.

You can query these DMVs using XMLA (XML for Analysis) statements within SSMS.

Example XMLA query to get active sessions:


<Discover xmlns="http://schemas.microsoft.com/analysisservices/2003/xmla">
  <RequestType>DISCOVER_SESSIONS</RequestType>
  <PropertyList>
    <DataSourceInfo>Provider=MSOLAP;Data Source=YourServerName;</DataSourceInfo>
    <Format>Tabular</Format>
  </PropertyList>
</Discover>

SQL Server Profiler

While often used for relational databases, SQL Server Profiler can also be configured to trace events from Analysis Services. This is invaluable for debugging and performance analysis of specific queries or operations.

Third-Party Monitoring Tools

Numerous third-party tools offer advanced monitoring, alerting, and reporting capabilities specifically designed for SQL Server and its components, including Analysis Services.

Conclusion

A robust monitoring strategy is essential for the health and performance of your Analysis Services deployments. By understanding the key areas to watch and leveraging the available tools, you can ensure your business intelligence solutions remain responsive, reliable, and efficient.

Continue to the next section to learn about specific configuration aspects for monitoring.