Trace an SAP HANA Client Connection

1. Enter the following command to see the current trace settings:

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   hdbsqldbc_cons SHOW ALL
   

   

   hdbsqldbc_cons utility can be found in the sap/hdbclient folder.

2. To specify the file location for the trace file and enable tracing of SQL statements, enter the following commands:

   Shell (Microsoft Windows)

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   hdbsqldbc_cons TRACE SQL ON LEVEL DEBUG
   mkdir c:\temp\traces
   hdbsqldbc_cons TRACE FILENAME c:\temp\traces\SQLDBC-%p.txt
   

   Shell (Linux or Mac)

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   hdbsqldbc_cons TRACE SQL ON LEVEL DEBUG
   mkdir /tmp/traces
   hdbsqldbc_cons TRACE FILENAME /tmp/traces/SQLDBC-%p.txt
   

   The %p will be replaced with the process ID of the traced application. Including %p in the file name ensures that each process can write its own trace file.

   The next step provides an example of sending the trace output to stdout or stderr. Another option for Node.js applications is to specify a callback to receive the trace output to using the onTrace method which is shown in the tutorial Connect Using the SAP HANA Node.js Interface

   Trace categories:

   • SQL
   • DEBUG
   • PACKET
   • DISTRIBUTION

   Trace levels:

   • DEBUG
   • INFO
   • WARNING
   • ERROR
   • FATAL

   For more information, see SQLDBC Tracing and Trace Options.

3. Run the following command to connect to HDBSQL and query for the status. Since tracing is enabled, a trace file will be generated and can be used to see which SQL statements are called by \s.

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   hdbsql -U User1UserKey "\s"
   

4. Find and open the generated trace file. Remember to replace #### to match the trace file name you wish to open.

   Shell (Microsoft Windows)

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   cd c:\temp\traces
   dir SQLDBC*.txt /od
   notepad SQLDBC-####.txt
   

   Shell (Linux or Mac)

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   cd /tmp/traces
   ls -lt
   pico SQLDBC-####.txt
   

   

   Notice that the trace settings are shown at the top of the file.

   libSQLDBCHDB 2.12.13.1642791468
   SYSTEM: Microsoft Windows / X64
   BUILD AT: 2022-01-28 19:09:11
   BRANCH: unknown
   BUILD MODE: rel
   APPLICATION: c:\SAP\hdbclient\hdbsql.exe
   HOST: W-R90XC65K
   OS USER: dan
   CURRENT DIRECTORY: c:\SAP\hdbclient
   TRACE FILE NAME: c:\temp\traces\SQLDBC-23380.txt
   PROCESS ID: 23380
   TRACE FILE WRAP COUNT: 0
   
   ---
   Enabled Traces:
   
   SQL Trace: Level DEBUG
   Distribution Trace: Level DEBUG
   
   ---
   

   If the trace settings change while tracing is enabled, the Enabled Traces section will appear again in the trace file.

   If you are experiencing issues with SQLDBC tracing, consult Troubleshooting SQLDBC Tracing.

5. Search through the trace file and notice the SQL statements that were executed.

   ::EXECUTE WITH COMMIT SQLCURS_1 2020-12-28 07:11:09.717000 [0x000000000319c260]
   SQL COMMAND : SELECT VERSION FROM SYS.M_DATABASE
   ...
   ::EXECUTE WITH COMMIT SQLCURS_1 2020-12-28 07:11:09.729000 [0x000000000319c260]
   SQL COMMAND : SELECT B.HOST || ':' || SQL_PORT FROM PUBLIC.M_CONNECTIONS A JOIN SYS.M_SERVICES B   ON A.HOST = B.HOST and A.port = B.port   WHERE OWN = 'TRUE'
   

6. To turn off tracing for all categories, run the following command:

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   hdbsqldbc_cons TRACE OFF
   

The following are some additional options for tracing.

1. The FLUSH setting, when turned on, can reduce I/O activity. If you are investigating a crash, it should be turned on to ensure that all the trace information is recorded.

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   hdbsqldbc_cons TRACE FLUSH ON
   

2. Note that tracing should be turned off when not in use, as it does have a performance, memory and disk size impact. The following are some additional options to limit the trace file size to 100 KB (plus an archive file) and to turn on tracing only when a specific error code occurs. Error code 10 occurs when invalid credentials are used.

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   hdbsqldbc_cons TRACE SIZE 100K
   hdbsqldbc_cons TRACE ONLY ON ERROR 10
   

3. In situations where hdbsqldbc_cons is not accessible, perhaps because a driver was installed directly using npm or pip, trace settings can be set using environment variables.

   Shell (Windows)

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   set HDB_SQLDBC_TRACEFILE=c:\temp\traces\SQLDBC-%p.txt
   set HDB_SQLDBC_TRACEOPTS=SQL=DEBUG,FLUSH
   

   Shell (Linux or Mac)

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   export HDB_SQLDBC_TRACEFILE=/tmp/traces/SQLDBC-%p.txt
   export HDB_SQLDBC_TRACEOPTS=SQL=DEBUG,FLUSH
   

   Trace settings in environment variables take precedence over those set using hdbsqldbc_cons.

   The environment variable values can be seen and removed with the following commands. The first and last commands display what the environment variable is set to. The middle command removes the value of the environment variable.

   Shell (Windows)

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   set HDB_SQLDBC_TRACEFILE
   set HDB_SQLDBC_TRACEFILE=
   set HDB_SQLDBC_TRACEFILE
   
   set HDB_SQLDBC_TRACEOPTS
   set HDB_SQLDBC_TRACEOPTS=
   set HDB_SQLDBC_TRACEOPTS
   

   Shell (Linux or Mac)

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   printenv | grep HDB_SQLDBC_TRACE
   unset HDB_SQLDBC_TRACEFILE
   unset HDB_SQLDBC_TRACEOPTS
   printenv | grep HDB_SQLDBC_TRACE
   

   

4. Trace information can be directed to stdout or stderr. See below for a few examples.

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   hdbsql -U User1UserKey -Z traceFile=stdout -Z traceOptions=sql=warning "SELECT * FROM HOTEL.CUSTOMER"
   

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   set HDB_SQLDBC_TRACEOPTS=SQL=WARN
   set HDB_SQLDBC_TRACEFILE=stdout
   hdbsql -U User1UserKey "SELECT * FROM HOTEL.CUSTOMER"
   set HDB_SQLDBC_TRACEOPTS=
   set HDB_SQLDBC_TRACEFILE=
   

5. Tracing can also be enabled in an applications connection properties. For further details see traceFile and traceOptions in SQLDBC Connection Properties.

Java must be installed in order to complete the following steps. To check if it is installed, run the following commands:

java -version
javac -version

1. To show the current JDBC tracing configuration, run the following command:

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   java -jar c:\sap\hdbclient\ngdbc.jar SHOW
   

   Alternatively the trace settings can be viewed and set using a GUI.

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   java -jar c:\sap\hdbclient\ngdbc.jar
   

   

2. Turn on the tracing for SQL statements using either the GUI or the commands below:

   Shell

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   java -jar c:\sap\hdbclient\ngdbc.jar TRACE ON
   java -jar c:\sap\hdbclient\ngdbc.jar TRACE FILENAME c:\temp\traces\jdbctrace
   java -jar c:\sap\hdbclient\ngdbc.jar TRACE API ON
   

   The different command-line option keywords can be found at JDBC Tracing and Trace Options.

3. Execute a query which will generate a trace file.

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   java -jar c:\sap\hdbclient\ngdbc.jar -k User1UserKey -o encrypt=True -o validatecertificate=false -c "SELECT * FROM HOTEL.CUSTOMER"
   

4. Examine the trace file.

   <html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body><PRE><PLAINTEXT>
   Java version:   11
   ClassLoader:    jdk.internal.loader.ClassLoaders$AppClassLoader@30946e09
   Process ID:     7984
   Driver version: package com.sap.db.jdbc, Java Platform API Specification, version 1.8, SAP HANA JDBC Driver, SAP SE, 2.7.9-e7d7d91fad7f2973ba232a4bff888b86d102c42b
   
   Trace configuration:
     Levels:                                       API
     Show plain-text client-side encrypted values: Disabled
     Show timestamps:                              Disabled
     Show elapsed times:                           Disabled
     Trace file size:                              Unlimited
     Stop on error:                                Disabled
   
   ---- Thread 1060b431 main
   com.sap.db.jdbc.Driver@2ac273d3.connect("jdbc:sap://localhost:30015", {encrypt=True, key=***, validatecertificate=false})
   => com.sap.db.jdbc.HanaConnectionClean@78a2da20[ID:203274]
   com.sap.db.jdbc.HanaConnectionClean@78a2da20[ID:203274].createStatement()
   => com.sap.db.jdbc.HanaStatement@47d9a273
   com.sap.db.jdbc.HanaStatement@47d9a273.execute("SELECT * FROM HOTEL.CUSTOMER")
   

5. Tracing information can be sent to stdout or stderr as shown below.

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   java -jar c:\sap\hdbclient\ngdbc.jar -k User1UserKey -o traceFile=stdout -o traceOptions=CONNECTIONS -c "SELECT * FROM HOTEL.CUSTOMER"
   

6. Tracing can also be enabled via the connection parameters. For further details see Trace a JDBC Connection Using a Connection String.

Congratulations, you have now configured tracing with the SAP HANA Client!