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Oracle backup or restore fails to find an available port to start IOServer

Updated over 3 weeks ago

Problem description

Oracle backup or restore fails with Oracle_DTC 17: Failed to establish session with GRPC Server or the detailed logs will contain the error “Failed to find an available port to start IOServer”

Cause

  1. The Oracle DTC agent is unable to start the IOServer process due to a port conflict on the Oracle database server. The IOServer process will use a dynamic port range of 20000-20050 by default.

  2. The server hostname is not properly configured with the /etc/hosts file.

Traceback

level=info ts=2023-09-18T13:36:25.933427377-04:00 filename=backup.go:2042 message="Starting PhoenixIOServer"
level=error ts=2023-09-18T13:36:25.941451785-04:00 stack="No port is available in the given range : from 20000 to 20050\\ngoroutine 67 [running]:\nruntime/debug.Stack()\n\t/usr/local/go/src/runtime/debug/stack.go:24 \n\t/bld/src/phoenix/oraclesbt/client/agent/backup/backup.go:2538level=info ts=2023-09-18T13:36:25.941598151-04:00 filename=backup.go:1684 message="Finishing backup operation with error status" ErrorCode=4295819281 Message="Failed to find an available port to start IOServer"

Verification:

  1. IOServer process port conflict

    • Verify what process or application is using the ports by running one of the following commands below. These are only examples, and please feel free to use any command familiar to you, or available on the Oracle database server.

      netstat -lntup | grep ":200[0-9][0-9]"

      ss -lntu | grep ":200[0-9][0-9]"

  2. Hostname Verification

    • Ping the server’s hostname - ping $(hostname)

      • Ping should return the IPv4 address, not IPv6

    • Check the /etc/hosts file

      • There should be an entry for the server’s correct hostname and IPv4 address

Resolution

  1. IOServer process port conflict (Phoenix Agent below 7.0)

    1. The port range can be moved following the process below

    2. Stop the PhoenixOracle service: service PhoenixOracle stop

    3. Edit the following file: /etc/PhoenixOracle/Phoenix.yml

    4. Update the following entries with an available port range of at least 50 ports:

      IOSERVER_START_PORT: 20000

      IOSERVER_END_PORT: 20050

    5. Start the PhoenixOracle service: service PhoenixOracle start

  2. Hostname Resolution (Valid for all agents)

    1. Update the /etc/hosts file with an entry for the hostname and IPv4 address

See also

Related Articles
Prerequisites for Oracle servers
Troubleshooting Oracle DTC issues
Troubleshooting common Oracle Direct to Cloud issues
Backup failing with the error ORACLE not available
Backup/Restore Failure – Error While Connecting to IOServer Process [Failed to Establish Session with GRPC Server]
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