NCM capture of large device configuration (greater than 40000 lines) is truncated


Article ID: 211431


Updated On:


CA Spectrum


A NCM capture of a large configuration for a device may not complete and may result in the captured configuration being truncated.


The following error may be seen in the NCMSERV.OUT log file:

Mar 04, 2021 12:27:29 PM io.grpc.netty.NettyServerHandler onStreamError
WARNING: Stream Error
io.netty.handler.codec.http2.Http2Exception$StreamException: Stream closed before write could take place


SPC-OCC-10746: The operation failed. SPC-NCM-20007: Capture Running Script Returned Error [-99]: Received message larger than max (5254178 vs. 4194304).


I ran the Host Configuration debug from the console and got this:

Apr 13, 2021 13:54:51.472 (PoolThread-74: GlobalPool => CaptureAction.actionPerformed) (HOSTCONFIG) - HostConfig - Capture results: ModelActionResults: errorMsg: null, values: [Attribute: 0x1 = SPC-NCM-20007: Capture Running Script Returned Error [-99]:  Received message larger than max (5111090 vs. 4194304), Attribute: 0x2 = false, Attribute: 0x3 = 1, Attribute: 0x0 = 0, Attribute: 0x0 = 0, Attribute: 0x0 = 0, Attribute: 0x0 = 0]


The default max receive message size is 4MB, which is not large enough and causes the failure





DX NetOPs Spectrum 20.2.5


This will be resolved in DX NetOps Spectrum 20.2.10 (aka and above.  There is no fix for 20.2.7 (aka

If you are running Spectrum you can open a case with Broadcom support and request patch Spectrum

The fix will change the default Max Receive message size to 64MB.


NCM running configuration failed in the case of large configuration files.


NCM GRPC communication channel maximum receives message size set to default value 4MB. Changed the Receive message size to 64MB. (DE496405, 32582829 ,

Additional Information


You may need to also set the following in $SPECROOT/NCM/config.xml:

<diff-largefile type="java.lang.String">on</diff-largefile>
<jsch-read-datawait type="java.lang.Integer">8</jsch-read-datawait>
<jsch-read-datawait-mutipler type="java.lang.Integer">30</jsch-read-datawait-mutipler>

In case you should see any OutOfMemory errors when running the configration capture, set the following in $SPECROOT/lib/SDPM/partslist/NCMSERV.idb

ARGV;$SPECROOT/bin/JavaApps/bin/ncmservice<CSEXE> -Xms256M -Xmx8192M

Restart the ncmservice after making the above changes.