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“resource temporarily unavailable”

or “connection refused”

  • Error Details

“connection pending after…”

or “connection refused”

The issue can occur when logon load balance is used or not. The only difference is to where the hostname used should be pointing (directly to an ABAP instance or to the Message Server).

The target port would be different too:

- For a direct connection to an ABAP instance, the port is 32XX (where “XX” is the instance number).

- When logon load balance is used, the initial connection to the Message Server is done to the port 36XX by default.

- The “services” file is not needed anymore, at the frontend computer. With the new SAPUILandscape.xml file in SAP Logon, the port numbers are stored in the SAPUILandscape.xml file itself.

If the SAPUILandscape.xml is not used and an entry is being added manually, then provide the port number together with the Message Server hostname using the syntax “hostname:port” (for example:

Possible root cause #1: configuration issue.

  • Possible solution: confirm that the hostname and Instance Number (or port number, if logon load balance is used) are correct.
  • SAP Support component: if this is a configuration problem with the port number and hostname not getting stored in the SAPUILandscape.xml, then BC-FES-GUI can help.

Possible root cause #2: DNS/Network/Firewall issue.

  • Possible solution: involve the DNS/network/firewall team, so they fix the issue.
  • SAP Support component: being something related to customer’s network / infrastructure, BC-NET can provide some guidance.

Possible root cause #3: the target SAP system is down

  • Possible solution: confirm that the target SAP system is up or start it.
  • SAP Support component: BC-CST-STS can assist with starting it up, if required.

Additional tests that can be performed :

  • “ping <hostname>” – confirm that the IP address returned by “ping” is correct:

  • “telnet <hostname> <32xx or 36xx>”, where “xx” is the Instance Number. The “telnet” tool is delivered by the operating system, not by SAP.

       If “telnet” is able to connect, the whole window becomes “empty”, like:

  • Confirm that the backend system is up and running by logging on to the server at operating system level, either with “SIDadm” (or with a local administrator, on Windows servers), and executing the command below at a command prompt window started “as administrator” (“XX” is the instance number):
    • sapcontrol -nr XX -function GetProcessList

      On Windows servers, it might be required to add “-prot PIPE” to the command line:

      sapcontrol -prot PIPE -nr XX -function GetProcessList

  • Confirm that the correct Message Server port number is used. With the new SAPUILandscape.xml file, the “services” file is not needed at the frontend computer, and the correct port number should be stored in the SAPUILandscape.xml file.
    • At the target SAP system, execute the transaction SMMS. The information on the header should reveal the port number:

If the SAP version is old, the header would not be there. Then, get the “dev_ms” trace file and verify the port number at the beginning of the trace. Example:

trc file: "dev_ms", trc level: 1, release: "753"
[Thr 5592] Wed Jul 01 14:28:32 2020
[Thr 5592] SAP_RELEASE = 753
[Thr 5592] compatibility level = 0
[Thr 5592] Server state INIT
[Thr 5592] MsSSetTrcLog: trc logging active, max size = 52428800 bytes
[Thr 5592] * SWITCH TRC-RESOLUTION from 1 to 10
systemid   562 (PC with Windows NT)
relno      7530
patchlevel 0
patchno    602
intno      20170305
make       multithreaded, Unicode, 64 bit, optimized
pid        3808

[Thr 5592] Wed Jul  1 14:28:32:668 2020
[Thr 5592] ***LOG Q01=> MsSInit, MSStart (Msg Server 1 3808) [msxxserv.c   2752]
[Thr 5592] load acl file = D:\usr\sap\N50\SYS\global\ms_acl_info.DAT
[Thr 5592] List of entries found in D:\usr\sap\N50\SYS\global\ms_acl_info.DAT
[Thr 5592] [001] * [::] (VALID)
[Thr 5592] MsGetOwnIpAddr: my host addresses are :
[Thr 5592]   1 : []  (HOSTNAME)
[Thr 5592]   2 : []  (LOCALHOST)
[Thr 5592] MsHttpInit: full qualified hostname = testn50
[Thr 5592] HTTP logging is switch off
[Thr 5592] set HTTP state to LISTEN
[Thr 5592] *** HTTP port 8101 state LISTEN ***
[Thr 5592] *** I listen to port sapmsN50 (3601) ***
[Thr 5592] *** I listen to internal port 3901 (3901) ***
[Thr 5592] *** HTTP port 8101 state LISTEN ***
[Thr 5592] CUSTOMER KEY: >C1861165945<
[Thr 5592] compatibility level = 0
[Thr 5592] build version=753.2019.10.18
[Thr 5592] read logon groups from previously stored file N50_msg_server_adtl_storage
[Thr 5592] Server state ACTIVE

[Thr 5592] Wed Jul  1 14:28:51:411 2020

  • The SAP wiki lists options of how to get the trace files of the backend server. The port number could also be obtained from ‘services’ file on SAP server where the Message Server is running.

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