DS/DPS: DPS Error: Unable to read SEARCH response from backend server : Connection closed by the peer backend server (EOF received). - DS Error: B4 - Server failed to flush BER data back to client (Doc ID 1339963.1)

Last updated on OCTOBER 11, 2016

Applies to:

Oracle Directory Server Enterprise Edition - Version 6.3 SP1 and later
Information in this document applies to any platform.
***Checked for relevance on 24-05-2013***

Symptoms

Problem description (DS access log/ DPS access log)

 

 
It is reported from time to time  the following error message in
DS access log:
  • "B4 - Server failed to flush BER data back to client "
DPS access log:
  •  Unable to read SEARCH response from backend server : Connection closed by the peer backend server (EOF received)    

 

Explanation of B4 error message

http://download.oracle.com/docs/cd/E19261-01/820-2765/baasd/index.html

The server failed to flush data response back to client. This code can occur when the client closes the connection to the server, before the server finished sending data to the client.

With DS/DPS deployment this B4 DS error means that DPS has closed the connection with DS before DS has finished off sending data. Therefore DS is issuing this error message to indicate that DPS has closed the connection abruptly

 

Checking the correlation of DS and DPS error message 

 

DS access logs:

[07/Jul/2011:16:36:03 +0200] conn=31 op=2 msgId=4 - SRCH base="o=group1,dc=example,dc=com" scope=2 filter="(computerInfo=OR-LEG_*)" attrs="objectClass subschemaSubentry objectClass subschemaSubentry"
[07/Jul/2011:16:40:04 +0200] conn=31 op=2 msgId=-1 - closing from X.Y.Z.T:52601 - B4 - Server failed to flush BER data back to client -
[07/Jul/2011:16:40:04 +0200] conn=31 op=-1 msgId=-1 - closed.



DPS access logs:

[07/Jul/2011:16:36:03 +0200] - SERVER_OP - INFO - conn=12 op=2 SEARCH base="o=group1,dc=example,dc=com" scope=2 filter="(computerInfo=OR-LEG_*)" attrs="objectClass subschemaSubentry objectclass subschemaSubentry " s_msgid=4 s_conn=rmx150107:36
[07/Jul/2011:16:40:07 +0200] - OPERATION - INFO - conn=12 op=2 SEARCH RESPONSE err=1 msg="Unable to read SEARCH response from backend server : Connection closed by the peer backend server (EOF received)." nentries=13932 etime=243953


Note:
It is very important to establish the correlation between a given DS and DPS request, to follow exactly how DPS is handling it.

Here it is also worth noticing that this request which is failing is manipulating a very large number of entries when it is falling over, as the filter will match many entries.






Cause

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