I have run into a few install issues with OBIEE the last couple years, and some of them have been odd enough I feel necessary to document -- Both for my sanity and yours. Today I will cover connectivity issues with the RCU database.
OBIEE 11g (126.96.36.199.141014)
This one was a real head-scratcher. I would start a fresh install of OBIEE 11g, but in certain network environments coreapplication_obisch1 would fail to start. The error logs would show things like this:
[2013-05-08T15:55:10.000-05:00] [OracleBISchedulerComponent] [ERROR:1]   [ecid: 004r3gaH1w^6iK3Lzmw0yW0000ft000000] [tid: a1d08700] [nQSError: 17011] SQL statement execution failed. [[ [nQSError: 17001] Oracle Error code: 3135, message: ORA-03135: connection lost contact Process ID: 24076 Session ID: 15 Serial number: 32281 at OCI call OCIStmtExecute: SELECT JOB_ID , RELATIVE_ORDER , JOB_PARAM , DELETE_FLG FROM S_NQ_JOB_PARAM WHERE 1 = 0.
Running tcpdump on OBIEE server and Database server would show traffic flow, and first glance of firewall logs showed no denies. Then I discovered that some Oracle developer decided to be fancy and use URG packets for just PART of the scheduler component. I had never even heard of URG packets before!
To watch for URG packets using tcpdump, try this on both servers
tcpdump 'tcp & 32 != 0'. In my case I saw the packets leave the OBIEE server, but never make it to the database server. Example of packet output:
12:39:44.727770 IP obiee-d03.domainname.48902 > obitest-db1.domainname.ricardo-lm: Flags [P.U], seq 1168:1169, ack 1804, win 371, urg 1, options [nop,nop,TS val 1642810414 ecr 1621708054], length 1
I tried looking for an Oracle Doc that I had the detailed this issue, but I can no longer find it. I do know it affects Version 188.8.131.52.0 and later. Jeremy Stretch has a good writeup about URG packets here -- Which I enjoy because he mentions that it "isn't employed much by modern protocols" and it was "surprisingly difficult to find other uses of it in real-world captures".
OBIEE 12c (184.108.40.206)
Oracle Advanced Security
During the install of OBIEE 12c components would fail to start. This seemed strange to me because I have many 11g RCUs running on the same database server without issue. The log files did not show anything useful.
Luckily I quickly remembered that the DBA had recently enabled Oracle Advanced Security (encryption/verification), and started digging deeper. I asked the DBA to disable OAS, and sure enough it installed fine. Then I had him enable it again, and I restarted OBIEE -- Which failed.
Followed Oracle Support Doc 2121702.1, and the fix was simple: Added
EncryptionLevel=1 to both
biplatform_datasource in the odbc.ini file, but this was a post install task. I will still require that the DBAs disable OAS during the install/configure process, until I can get to the point of modifying the odbc.ini file.
Business Intelligence Suite Enterprise Edition - Version 220.127.116.11.0 to 18.104.22.168.0 [Release 12g]
Oracle Database - Enterprise Edition - Version 22.214.171.124 and later