How to verify the prerequisites using vertica validation utilities before install or upgrade of Data Repository in CA Performance Management?
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How to verify the prerequisites using vertica validation utilities before install or upgrade of Data Repository in CA Performance Management?

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Article ID: 43260

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Updated On:

Products

CA Performance Management - Usage and Administration DX NetOps

Issue/Introduction

How can the prerequisites for install/upgrade of the Data Repository by verified using Vertica validation utilities?

Environment

CAPM 21.x

CAPM 22.x

Resolution

Before upgrading the data repository following steps need to be completed to check if the server meets the minimum requirements.

  • Verify that the Data Repository host has at least 2 GB of swap space.
  • Verify that the Data Repository hosts use the ext4 or ext3 file system for data and catalog directories.


    Note:
     The database performs best with the ext4 file system.

  • Verify that you are not using Logical Volume Manager (LVM) for data and catalog directories.

 

Verify Hardware and Network Performance

Vertica provides a set of utilities that test the performance of your hardware for the Data Repository. To verify that the environment is ideal for the database, run these tests before you upgrade the Data Repository.


Note:
 If you have already installed the Data Repository, you can perform these tests at any time to verify performance. The utilities are available on each node in /opt/vertica/bin.

If the tests do not meet the recommendations, fix the issues before you continue the installation or upgrade.

 

vcpuperf

This utility measures the CPU processing speed of the host and compares the speed against benchmarks for common server CPUs. The utility measures how long the server requires to complete the test, and determines whether CPU throttling is enabled.

Follow these steps:

Execute the following command on each Data Repository node:

./vcpuperf > /tmp/vcpuperf.out

 

Verify that the  performance meets the following requirements

The CPU time is consistent with the benchmark values in the output.

The low load time and high load time are within 10 microseconds. If the difference is grater than 50 microseconds, CPU throttling might be enabled on your system. Disable CPU throttling.

Example:

The following example shows the return from this utility:

$ /opt/vertica/bin/vcpuperf

Compiled with: 4.1.2 20080704 (Red Hat 4.1.2-52)
Expected time on Core 2, 2.53GHz: ~9.5s
Expected time on Nehalem, 2.67GHz: ~9.0s
Expected time on Xeon 5670, 2.93GHz: ~8.0s
This machine's time:
CPU Time: 7.740000s
Real Time:7.740000s

Some machines automatically throttle the CPU to save power.

This test can be done in <100 microseconds (60-70 on Xeon 5670, 2.93GHz).

Low load times much larger than 100-200us or much larger than the corresponding high load time

indicate low-load throttling, which can adversely affect small query / concurrent performance.

This machine's high load time: 67 microseconds.
This machine's low load time: 64 microseconds.

This test was performed on a system with 2.67-GHz processors, so the real time is acceptable. The difference between the high load time and low load time is within the expected tolerance.

For more information about this utility, see the Vertica documentation.

 

vioperf

This utility tests the performance of the disk input and output (I/O). The utility performs a series of reads and writes.

Follow these steps:

Execute the following commands on each Data Repository node:

./vioperf /data > /tmp/vioperf.out --duration=60sec

 

/data is the full path of the data directory.

./vioperf /catalog > /tmp/vioperf.out --duration=60sec

 

/catalog is the full path of the catalog directory.

Verify the Write and Read counter values at least 40 MB/s per core.

The recommended I/O is 40 MB/s per physical core on each node. For example, the recommended I/O rate for a node with 2 hyper-threaded six-core CPUs (12 physical cores) is 480 MB/s.

 

Important! If the thread count column shows a value of 1, the utility cannot determine the number of cores. Add the following arguement to the command to run the utility:

--thread-count=CORES

Cores defines the number of cores in the system as a fixed integer.

 

Example:

The following example shows the return from this utility for the data directory:

 

The minimum required I/O is 20 MB/s read and write per physical processor core on each node, in full duplex i.e. 

reading and writing at this rate simultaneously, concurrently on all nodes of the cluster. The recommended I/O 

is 40 MB/s per physical core on each node. For example, the I/O rate for a server node with 2 hyper-threaded 

six-core CPUs is 240 MB/s required minimum, 480 MB/s recommended.Using direct io (buffer size=1048576, alignment=512) for directory "/drdata"

 

test directory counter
name
counter
value 
counter
(value 10 sec avg)
Counter value /
core 

counter value/core
(10 sec avg)

 thread
count
%CPU %IO Wait elapsed
time (s)
remaining
time (s)
Write /drdata MB/s 873 873 54.5625 54.5625  16 29 40 10 5
Write /drdata MB/s 868 868 54.25 54.0625 16 28 30 15 0
ReWrite /drdata (MB-read+MB-write)/s 275+275 275+275 17.1875+17.1875   17.1875+17.1875  16 13 21 10 5
ReWrite /drdata (MB-read+MB-write)/s 242+242 178+178 15.125+15.125    11.125+11.125   16 7 17 15 0
Read /drdata MB/s 735 735 45.9375 45.9375 16 11 23 10 5
Read /drdata MB/s 786 786 49.125 49.125 16 26 25 15 0
SkipRead /drdata  seeks/s  4511 4511 281.938 281.938 16 14 19 10 5
SkipRead /drdata  seeks/s  4477 4407 279.812 275.438 16 3 15 15 0
 

This server has 16 cores. The Read and Write counter values indicate the I/O is greater than 40 MB/s per core.

For more information about this utility, see the Vertica documentation.

 

vnetperf

This utility tests the network performance of the Data Repository hosts. The utility measures network latency and the throughput for the TCP and UDP protocols.


Important!
 This utility causes a high network load and affects database performance. Do not run this utility while the database is running.


Follow these steps:

  1. Log in as a user that has passwordless ssh between the nodes.
  2. Execute the following command on one of the Data Repository nodes:

./vnetperf --hosts DAhost,DRhost1,DRhost2,DRhost3 > /tmp/vnetperf.out

Specify the hostname or IP address of the Data Aggregator host and each Data Repository host.

Verify that the network performance meets the following requirements:

  • Round-trip time (RTT) latency of 200 microseconds or less
  • Clock skew under 1 second
  • Throughput of 800 MB/s or more
    The utility runs a series of throttled tests. Verify the throughput for the highest speed test.

 

Additional Information

For more information about this utility, see the Vertica documentation.

Please refer to the following wiki link for more information 

https://techdocs.broadcom.com/us/en/ca-enterprise-software/it-operations-management/performance-management/21-2/administrating/data-repository-administration/run-data-repository-diagnostic-utilities.html

Note: We don't have any docs on cpu throttling disablement.  It's a BIOS thing and all BIOS are different.  Here is an example from googling for "disable cpu throttling in bios":

https://www.thomas-krenn.com/en/wiki/Disable_CPU_Power_Saving_Management_in_BIOS

Depending on the BIOS maker for your PC's running Vertica, setting options may change in BIOS.