11 Troubleshooting Oracle Sharding

You can enable tracing, locate log and trace files, and troubleshooting common issues.

The following topics describe Oracle Sharding troubleshooting in detail:

11.1 Oracle Sharding Tracing and Debug Information

The following topics explain how to enable tracing and find the logs.

11.1.1 Enabling Tracing for Oracle Sharding

Enable PL/SQL tracing to track down issues in the sharded database.

To get full tracing, set the GWM_TRACE level as shown here. The following statement provides immediate tracing, but the trace is disabled after a database restart.

ALTER SYSTEM SET EVENTS 'immediate trace name GWM_TRACE level 7';

The following statement enables tracing that continues in perpetuity, but only after restarting the database.

ALTER SYSTEM SET EVENT='10798 trace name context forever, level 7' SCOPE=spfile;

It is recommended that you set both of the above traces to be thorough.

To trace everything in the Oracle Sharding environment, you must enable tracing on the shard catalog and all of the shards. The traces are written to the RDBMS session trace file for either the GDSCTL session on the shard catalog, or the session(s) created by the shard director (a.k.a. GSM) on the individual shards.

11.1.2 Where to Find Oracle Sharding Alert Logs and Trace Files

There are several places to look for trace and alert logs in the Oracle Sharding environment.

Standard RDBMS trace files located in diag/rdbms/.. will contain trace output.

Output from ‘deploy’ will go to job queue trace files db_unique_name_jXXX_PID.trc.

Output from other GDSCTL commands will go to either a shared server trace file db_unique_name_sXXX_PID.trc or dedicated trace file db_unique_name_ora_PID.trc depending on connect strings used.

Shared servers are typically used for many of the connections to the catalog and shards, so the tracing is in a shared server trace file named SID_s00*.trc.

GDSCTL has several commands that can display status and error information.

Use GDSCTL STATUS GSM to view locations for shard director (GSM) trace and log files.

GDSCTL> status
Alias                     SHARDDIRECTOR1
Start Date                25-FEB-2016 07:27:39
Trace Level               support
Listener Log File         /u01/app/oracle/diag/gsm/slc05abw/sharddirector1/alert/log.xml
Listener Trace File       /u01/app/oracle/diag/gsm/slc05abw/sharddirector1/trace/
Endpoint summary          (ADDRESS=(HOST=shard0)(PORT=1571)(PROTOCOL=tcp))
GSMOCI Version            2.2.1
Mastership                N
Connected to GDS catalog  Y
Process Id                10535
Number of reconnections   0
Pending tasks.     Total  0
Tasks in  process. Total  0
Regional Mastership       TRUE
Total messages published  71702
Time Zone                 +00:00
Orphaned Buddy Regions:   None
GDS region                region1
Network metrics:
   Region: region2 Network factor:0

The non-XML version of the alert.log file can be found in the /trace directory as shown here.


To decrypt log output in GSM use the following command.

GDSCTL> set _event 17 -config_only

Master shard director (GSM) trace/alert files include status and errors on any and all asynchronous commands or background tasks (move chunk, split chunk, deploy, shard registration, Data Guard configuration, shard DDL execution, etc.)

To find pending AQ requests for the shard director, including error status, use GDSCTL CONFIG.

To see ongoing and scheduled chunk movement, use GDSCTL CONFIG CHUNKS -show_reshard

To see shards with failed DDLs, use GDSCTL SHOW DDL -failed_only

To see the DDL error information for a given shard, use GDSCTL CONFIG SHARD -shard shard_name

11.2 Common Error Patterns and Resolutions for Sharded Databases

See the following topics for information about troubleshooting common errors in Oracle Sharding.

11.2.1 Issues Starting Remote Scheduler Agent

If you encounter issues starting Remote Scheduler Agent on all the shard hosts, try the following:

To start Scheduler you must be inside ORACLE_HOME on each shard server.

[oracle@shard2 ~]$ echo welcome | schagent -registerdatabase 8080
Agent Registration Password?
Failed to get agent Registration Info from db: No route to host

Solution: Disable firewall

service ipchains stop
service iptables stop
chkconfig ipchains off
chkconfig iptables off

11.2.2 Shard Director Fails to Start

If you encounter issues starting the shard director, try the following:

To start Scheduler you must be inside ORACLE_HOME on each shard server.

GDSCTL>start gsm -gsm shardDGdirector
GSM-45054: GSM error
GSM-40070: GSM is not able to establish connection to GDS catalog

GSM alert log, /u01/app/oracle/diag/gsm/shard1/sharddgdirector/trace/alert_gds.log
GSM-40112: OCI error. Code (-1). See GSMOCI trace for details.
GSM-40122: OCI Catalog Error. Code: 12514. Message: ORA-12514: TNS:listener does not 
currently know of service requested in connect descriptor
GSM-40112: OCI error. Code (-1). See GSMOCI trace for details.
Process 1 in GSM instance is down
GSM shutdown is successful
GSM shutdown is in progress
NOTE : if not message displayed in the GSM log then enable GSM trace level to 16 
while adding GSM itself.
  1. Remove the newly created shard director (GSM) that failed to start.

    GDSCTL> remove gsm -gsm shardDGdirector
  2. Add the shard director using trace level 16.

    GDSCTL> add gsm -gsm shardDGdirector -listener port_num -pwd gsmcatuser_password
     -catalog hostname:port_num:shard_catalog_name
     -region region1 -trace_level 16
  3. If the shard catalog database is running on a non-default port (other than 1521), set the remote listener.

    SQL> alter system set local_listener='(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)

11.2.3 Errors From Shards Created with CREATE SHARD

For errors that occur during a DEPLOY from shards created with the GDSCTL CREATE SHARD command check the following:

  • Remote Scheduler Agent logs on shard hosts

  • DBA_SCHEDULER_JOB_RUN_DETAILS view on shard catalog

  • NETCA/DBCA output files in $ORACLE_BASE/cfgtoollogs on shard hosts

11.2.4 Issues Using Create Shard

The following are solutions to some issues that occur when using the GDSCTL CREATE SHARD command..

Make sure to create $ORACLE_BASE/oradata and $ORACLE_BASE/fast_recovery_area directories to avoid the following errors

GDSCTL> create shard -shardgroup primary_shardgroup -destination che -osaccount
 oracle -ospassword oracle
GSM-45029: SQL error
ORA-03710: directory does not exist or is not writeable at destination:
ORA-06512: at "SYS.DBMS_SYS_ERROR", line 86
ORA-06512: at line 1

GDSCTL>create shard -shardgroup primary_shardgroup -destination che -osaccount oracle
 -ospassword oracle
GSM-45029: SQL error
ORA-03710: directory does not exist or is not writeable at destination:
ORA-06512: at "SYS.DBMS_SYS_ERROR", line 86
ORA-06512: at line 1

Solution: Create oradata,fast_recovery_area under $ORACLE_BASE on all the shard hosts.

Privilege issues

GDSCTL>create shard -shardgroup primary_shardgroup -destination blr -credential cred
GSM-45029: SQL error
ORA-02610: Remote job failed with error:
STANDARD_ERROR="Launching external job failed: Login executable not setuid-root"
ORA-06512: at "SYS.DBMS_SYS_ERROR", line 86
ORA-06512: at line 1

Solution: Make sure to have root privilege on following directories,

chown root $ORACLE_HOME/bin/extjob
chmod 4750 $ORACLE_HOME/bin/extjob
chown root $ORACLE_HOME/rdbms/admin/externaljob.ora
chmod 640 $ORACLE_HOME/rdbms/admin/externaljob.ora
chown root $ORACLE_HOME/bin/jssu
chmod 4750 $ORACLE_HOME/bin/jssu

Error on create shard

GDSCTL>create shard -shardgroup primary_shardgroup -destination mysql02 -osaccount
 oracle -ospassword oracle
GSM-45029: SQL error
ORA-03719: Shard character set does not match catalog character set.
ORA-06512: at "SYS.DBMS_SYS_ERROR", line 79
ORA-06512: at line 1

Solution: Check the JAVA version, it must be the same on the shard catalog and all shard servers.

rpm -qa|grep java

11.2.5 Issues Using Deploy Command

GDSCTL> deploy
GSM-45029: SQL error
ORA-29273: HTTP request failed
ORA-06512: at "SYS.DBMS_ISCHED", line 3715
ORA-06512: at "SYS.UTL_HTTP", line 1267
ORA-29276: transfer timeout
ORA-06512: at "SYS.UTL_HTTP", line 651
ORA-06512: at "SYS.UTL_HTTP", line 1257
ORA-06512: at "SYS.DBMS_ISCHED", line 3708
ORA-06512: at "SYS.DBMS_SCHEDULER", line 2609
ORA-06512: at line 1

Solution : Check the $ORACLE_HOME/data/pendingjobs for the exact error. ORA-1017 is thrown if any issues on wallet.

  1. On problematic Shard host stop the remote scheduler agent.

    schagent -stop
  2. rename wallet direcotry on Database home

    mv $ORACLE_HOME/data/wallet $ORACLE_HOME/data/wallet.old
  3. start the remote scheduler agent and it will create new wallet directory

    schagent -start 
    schagent -status 
    echo welcome | schagent -registerdatabase 8080