Shared memory error with jcmon

[Former Member]

When I attempt to launch jcmon.bat and access local administration, I get the following error:

ERROR => Can't attach to administration shared memory (rc=3) [jcmonxx.c 219]

Any ideas? I'm pretty sure that server0 is not running, but since I can't log into the Visual Administrator or jcmon I don't know for sure.

Thanks in advance!

[Former Member]

Hi all,

I had the same error and it was just an stupid error in our case which I did want to share (you'll never know it might be the same problem in your case).

the reason that jcmon gives the error 'Can't attach to administration shared memory' is very logical. When the J2EE server hasn't started, jcmon can't reach its shared memory since it isn't there. Therefore this error does not mean anything else then look further why the j2ee server didn't start. The problem in our case was however that all the j2ee logs weren't filled so without error messages it will be difficult to solve the problem. And since the Abap system did startup succesfully I didn't had to look it those logs.

Finally after one day of irritation we found our reason. We changed something in the Abap Profiles, it is still unsure how it happend but with the change to the profile, the entries for STARTING the j2ee server disappeared. This way the j2ee server will never start, jcmon will only give errors because of this and the other log files will not be filled since they are not called!

The entries I am talking about are, for example: ms/server_port_0

jstartup/instance_properties

SDM_PROPERTIES

INSTANCE_PROPERTIES

jstartup/vm/home

exe/jlaunch

jstartup/protocol

jstartup/trimming_properties

icm/HTTP/j2ee_0

rdisp/frfc_fallback

rdisp/j2ee_timeout

rdisp/j2ee_start

rdisp/j2ee_start_control

rdisp/start_icman

If these are missing in your system, then that is the problem for sure. To solve the problem you have to logon to an working system and check the parameters there and adjust them to you parameters. If you have any questions, please feel free to mail me at nico.van.der.linden@logicacmg.com.

Hope this is usefull for you guys!

Kind regards,

Nico van der Linden...

[Former Member]

Nico van der Linden: thank you very much for your help.

Your answer help me to found the note:

Note 741289 - Profile parameters of the J2EE engine are lost

[Former Member]

Hi all,

I am facing the exact same problem when installing the JAVA addin to the NW04 ABAP stack.

dev_Jcmon reporting "Can't open shared memory administration (rc=3)". Also the jcmon.exe.log in the \programfiles\sapinst... directory gives the error as well.

My jstartup/vm/home parameter in the ABAP instance profile is correctly set to the right JAVA_HOME.

Also the sapinst log provides

==>

Output of I:\usr\sap/VIK/DVEBMGS00/j2ee/os_libs/jcmon.exe 'pf=I:\usr\sap\VIK\SYS\profile/VIK_DVEBMGS00_VIKLAB' is written to the logfile jcmon.exe.log

ERROR 2007-01-14 14:16:18

CJSlibModule::writeError_impl()

CJS-20057 Starting J2EE Engine DVEBMGS00 of SAP system VIK failed: after 21 seconds the state of the engine changed from "Stopping" to "Stopped".

TRACE [iaxxejsbas.hpp:270]

EJS_Base::dispatchFunctionCall()

JS Callback has thrown std::ESAPinstJSError: ind-rel.ind-os.ind-db.j2ee-eng.engineStartBadState

<==

I will be investigating into this further, and pasting logs and other stuff. Also I shall today also check out Nicos's lead on missing profile values. Are we sure that we dont need to upgrade the java related kernel files ? . I shall return back to this thread shortly after my latest trials to get over this agony 😐

regards, Vikram

[Former Member]

Note 741289 fixed my issue as well. Basically, all of the j2ee parameters per this note were wiped out (for no apparent reason; the note does not explain very well how the parameters just get wiped out). We had already completed multiple restarts with no previous issue. Anyway, this was a new server installation (J2EE add-on), so when this happened I did not have a full backup completed. So I manually added the NW2004s parameters (in the note) by cutting and pasting from another system's RZ10 parameters.

(I found the j2ee/instance_id number from the keydb.xml file in the j2ee add-on installation directory)

icm/HTTP/j2ee_0 PREFIX=/,HOST=localhost,CONN=0-500,PORT=5$$00

rdisp/frfc_fallback on

rdisp/j2ee_timeout 600

exe/j2ee $(DIR_EXECUTABLE)/jcontrol$(FT_EXE)

rdisp/j2ee_libpath $(DIR_EXECUTABLE)

rdisp/j2ee_start 1

rdisp/j2ee_start_control 1

j2ee/instance_id ID2224963

j2ee/dbdriver /oracle/client/10x_64/instantclient/ojdbc14.jar

jstartup/instance_properties $(jstartup/j2ee_properties):$(jstartup/sdm_properties

jstartup/release 700

jstartup/trimming_properties off

jstartup/protocol on

jstartup/vm/home /usr/java14_64

jstartup/max_caches 500

ms/server_port_0 PROT=HTTP,PORT=81$$

Edited by: Russell Johnson on Dec 16, 2008 3:20 PM