Monday, 21 November 2022

Runtime dump on SAP HANA

We can use below methods to Analyse HANA database Performance (Memory /CPU). 

Generating a runtime dump 
Creating a kernel profiler trace 
Using the HANA Dump Analyzer too

We will take about Runtime dump. remember one thing this in itself requires resources and may therefore worsen the situation. Hence it better to get Full System info Dumps using SAP HANA cockpit. 

There are a number of ways of recording runtime dumps:

1: SAP HANA cockpit

Alerting & Diagnostics   --> Manage full System information dumps --> Diagnosis File 
choose either a zip file from the list or create new one via Collect Diagnostics


2: From OS level using fullSystemInfoDump.py


1) Login as <sid>adm and run commands below:

..> cdpy
../python_support> python fullSystemInfoDump.py --rtedump --tenant=<tenant> --sets=3 --interval=5 --services=indexserver
The command above creates a set of 3 runtime dumps, for the indexserver, 5 minutes apart for the specified tenant for all hosts (hosts can be specified with --hosts=<hosts>)

To see a full list of options:

../python_support> python fullSystemInfoDump.py --help
2) Wait for the collection to finish.

The latest runtime dump collection can then be downloaded from:

 /usr/sap/<SID>/SYS/global/sapcontrol/snapshots> ls -latr | grep 'fullsystem*'


2) From the OS Level using hdbcons


1) Log into the linux HANA host presenting the issue as sidadm user;

2) Run command 'hdbcons';

3) On the hdbcons console run command below:

 > runtimedump dump

This will create a runtimedump for the host you logged in. The generated file will be under traces directory with naming like 'indexserver....rtedump.trc'.

4) Attach generated trace file to the OSS Message


3: From HANA Studio - SQL Editor


1) Log into HANA with a user with enough privileges to run procedure SYS.MANAGEMENT_CONSOLE_PROC;

2) Execute procedure SYS.MANAGEMENT_CONSOLE_PROC as a prepared statement;

3) Fill in parameter 1 with 'runtime dump dump' and parameter 2 with '<hostname>:<indexserver port>' (without quotes) and execute the statement;

4) Download the generated rtedump file and attach it to the message.

The screenshots below depict an example of how to record that dump in Studio:

4) From HANA Studio - Trace Collection

SAP HANA Studio SP8 adds the possibility of recording one or multiple samples of runtime dump based on a certain time frequency.

For instance, we can record a set of 5 runtime dumps, 1 every minute for every host or for a particular host only. Here are the steps:

1) Go to Administration -> Diagnosis Files;

2) Select "Diagnosis Information -> Collect...";

3) Set the option 'Create and collect one or multiple sets of runtime environment (RTE) dump file(s)';

4) Set the hosts, amount of samples (sets) and frequency on which the runtime dumps will be recorded;

5) Finish.

5) Using SQL Commands (available starting with HANA 2.0 SPS04):

ALTER SYSTEM CREATE RUNTIMEDUMP AT '<host>:<port>';

-- OR

CALL FULL_SYSTEM_INFO_DUMP_CREATE('--tenant=<SBID> --rtedump --sets=1 --services=indexserver --interval=1')

6) Known issues related to rtedump creation

 2040144 - SAP HANA DB: Collecting Diagnosis Information from the SAP HANA Studio can cause TLB shootdowns

Sunday, 20 November 2022

194685 - How to find work process trace for SM21 System Log or ST22 dump

 Symptom

This article introduces how to find the corresponding work process trace file for SM21 System log error or ST22 dump.

Work process trace file contains important information for SAP Support to analyze the root cause(especially for memory/kernel related issues).

Environment

SAP NetWeaver

Resolution

1. Find out on which application server and on which process did the error/dump occur:

  • Runtime Errors - ST22  

          Logon by EN, check "System environment" section:

 

 

  •     System Log - SM21

              The application server is displayed on the result list , then check “Nr” column for the work process number:

 



 






2. Switch to the application server from SM51, then search the trace file by ST11.

 





3. Download (save to txt file) and provide the work process trace file to SAP support if necessary.