Understanding Diagnostic Test Results in Windows HPC Server 2008

Applies To: Windows HPC Server 2008

Windows® HPC Server 2008 provides a set of commonly-used diagnostic tests. You can use these tests to help verify deployment, troubleshoot failures, and detect performance degradation.

Detailed results from the diagnostics tests are available as an HTML file. For information about viewing diagnostic test results in HPC Cluster Manager, see View and Save Test Results. You can also export test results to an HTML file by using the HPC PowerShell cmdlet Export-HpcTestResult.

Diagnostic tests are conceptually grouped by test suite. The following sections describe the tests in each suite and their results:

• Scheduler diagnostics

• Services diagnostics

• Connectivity diagnostics

• System Configuration diagnostics

• SOA diagnostics

• Performance diagnostics

Scheduler diagnostics

Job Submission Test

Submits a simple job to the HPC Job Scheduler Service using the clusrun command. This test verifies that the HPC Job Scheduler Service can accept and run a job on selected compute nodes.

Services diagnostics

All Services Running

Verifies that the required Windows HPC Server 2008 services are running on the selected nodes. Required services are determined by the role of the target node. This test may report the status of optional services, if they are present, but it only validates against the required services. For information about Service Oriented Architecture (SOA) services, use the SOA Service Configurations Report.

The following table lists the services, and indicates which services are required for each node role. If a service is listed as “Not validated”, that indicates that the test will not fail if that service is missing or not running.

Connectivity diagnostics

DNS Name Resolution

Verifies Domain Name System (DNS) name resolution between the selected compute nodes.

During the test, each node attempts to resolve the name of every other node in the cluster using DNS and compares the name with the HPC Management Service records. HPC Management Service records are updated dynamically by an agent running on the test node, ensuring the test is between the address recorded by DNS and the actual physical IP address of the node.

This test reports mismatches between pairs. Each local node performs its own DNS-only lookup, and then performs a host file and DNS lookup for each node in the cluster.

Domain Connectivity

Verifies connectivity between the selected nodes and each domain controller. It verifies connectivity by using a simple Lightweight Directory Access Protocol (LDAP) query to look up an Active Directory's RootDSE object.

Internode Connectivity

Verifies network connectivity between compute nodes by performing a ping test between each node and all other nodes in the selected group.

System Configuration diagnostics

Application Configurations Report

This test provides a report of the applications, including the version numbers, that are installed on the selected nodes.

In the Summary section of the test results, you can see a table that lists all of the installed applications, and a count of the nodes that have that application installed.

Expand the results for an individual node to see the applications installed on that node.

Firewall Configurations Report

This test reports on the firewall status (enabled or disabled) for the selected nodes. This test also reports the applications or services that are allowed access through the firewall (the firewall exceptions), including which port number they are using.

In the Summary section of the test results, you can see a table that summarizes the firewall status for the selected nodes. You can also see a table that lists all of the firewall exceptions, and a count of the nodes that have that firewall exception.

Expand the results for an individual node to see the firewall status, on a per-interface basis, and the firewall exceptions for that node.

Installed Software Updates Report

This test provides a report of the software updates (patches) that have been installed on each selected node. This test can take a long time.

You can expand the results for an individual node to see the list updates that have been installed on that node.

Network Configurations Report

This test provides a report of the network configuration for the selected nodes. For each relevant network (Private, Enterprise, and Application), this test reports the values for the following network settings:

• Description of the network adapter

• Speed

• Gateway

• DhcpEnabled (True/False)

• DhcpServer

• Domain

• DnsServers

• ID

• Interface Type

• IP Addresses

• Online (True/False)

• MAC Address

• Role

Expand the results for an individual node to see the network settings for that node.

Pending Software Updates

This test provides an overall report of the software updates that are available for all the nodes as well as a list of updates that are available for each node. The test reports on the updates that are identified as critical by Windows Server Update Services (WSUS) or Microsoft Update for each node in the cluster.  The diagnostic communicates with the Microsoft Update client, which filters the updates so that only those that are relevant to the node are reported to the diagnostic.

Expand the results for an individual node to see the pending updates for that node.

Service Configurations Report

This test provides a report of the services that are running on the selected nodes, and indicates the startup configuration for each service.

In the Summary section of the test results, you can see a table that lists all of the running services, and a count of the nodes that have that service running.

Expand the results for an individual node to see the running services for that node.

Software Updates Required

This test compares the software updates that are installed on the compute node with the updates specified in the node template Apply Updates task. The report indicates if any compute nodes failed to meet the required update level (None, Critical, All), or are missing the specific updates, as defined in the node template.

SOA diagnostics

SOA Model Latency

This test verifies network connectivity over Hypertext Transfer Protocol (HTTP) and NetTCP on the selected nodes or node groups.

This test attempts to detect a Windows Communication Foundation (WCF) broker node, and then runs the broker service on it. After a WCF broker node is detected, the test starts two Service-Oriented Architecture (SOA) sessions on each selected node: one session over HTTP and the other over NetTCP. The sessions are run sequentially on each of the selected nodes.

If an SOA session is successfully created on a node, the SOA Model test then sends one thousand messages to that session and counts the average latency of messages sent and received from each session. The test then sorts the latency results into three categories and reports the nodes in each category.

This test reports how many nodes fall into one of the three latency response categories. The following table describes the latency categories:

SOA Service Configurations Report

This test reports on the Service-Oriented Architecture (SOA) service configuration for the selected nodes. This test displays the following information:

• Service name

• Location of the service assembly

• Service type

• Contract type

• Architecture (x86 or x64)

• Environment variables

Performance diagnostics

MPI Ping Pong: Lightweight Throughput

This test measures the performance of the network throughput between each node and two of the nodes closest to it. This test is performed in a ring to provide a reasonable indication of cluster throughput in a minimal amount of time. Unlike latency measurements, throughput measurements stress a cluster’s network switches and few networking topologies and can provide fully non-blocking links under throughput measurement conditions where 4 MB packets are ping-ponging on all links.  Thus, each link is measured serially and ring-style where the first node ping-pongs with the node next to it, then that node ping-pongs with a node next to it, and so on until the ping-ponging moves around the entire set of nodes under test.  This method creates a Cycle Graph of the cluster network or N pairings of nodes (N=number of nodes under test) instead of the exponentially larger number of measurements required for a Complete Graph of the cluster network or N*(N-1)/2 pairings of nodes.

This test reports node latency in the following categories:

The test also reports the following statistics:

MPI Ping Pong: Quick Check

This test measures the bandwidth and latency of node-to-node communication. Since this is a performance test, to get accurate results, run this test on nodes that are offline and not running other jobs.

This test runs MPI Ping Pong between every pair of nodes. For a large number of nodes, this test might take a long time to complete. Specifically, for a target group of N nodes, the test will run against N*(N-1)/2 node-to-node connections serially. Average node latency and bandwidth is gauged for each connection, and results are categorized into high, medium, and low performance categories.

The same statistics are reported for this test as for the MPI Ping Pong: Lightweight Throughput test.