911: My HANA One system on AWS has fallen and it can't get back up - Indexserver crash

[Former Member]

Hi Juegen or anyone else from SAP,

   I was trying to load a 5GB CSV file into a ROW table and HANA's IndexServer crashed with a crashdump file. I have the stuff zipped up and copied to my local drive. A quick examination of the trace files show an issue in the indexserver. When I attempt to stop and start the HANA database, I always get the indexserver crash. I can't use SAP HANA Studio for anything. This is on the "production" HANA One instance I have on AWS with 63GB of ram, so I figured I'd be OK.  Right now, my server is useless.The good news is I have a backup.

Any suggestions before I kill the instance and recreated?

Thanks,

Bill

[former_member210781]

I have the same issue , please go through SAP Note 2081663

[Former Member]

Hi Bill,

I do not think it was the Row Tables, but the data load for the indexserver and HANA.

If loading 30G of DATA, using the HANA One 60G AWS instance and from the DF list of volume usage, it looks like you did not have enough room on HANA which is prob the root cause of the crash.

HANA requires 30 of the 60G from HANA One to run its application/services/etc - so in reality, there is only 30G of memory that is available. I know you are well versed and a HANA expert, as I have followed many of your posts, so if you knew this and does not apply - just trying to help!

Cheers!

[Former Member]

Hi Peter,

    You are quite right on the memory limits - especially in the case of row tables. I ended up with a scenario where the data loader added too much data to the system and ideally should have thrown an error during the load. It did - just too late. The row table ended up having more data than could load into memory and the server crashed. Unfortunately, I could never recover other than tearing down the instance and building a new instance - this time using column tables.

Regards,

Bill

[Former Member]

Hey Bill did you ever get to the bottom of this? I have this on a system.

[Former Member]

Hi John,

    I never did since I was working on AWS HANA One with a deadline and budget. I ended up terminating the instance and recreating it. I now stick to COLUMN tables. You would think the engine would have a threshold to prevent row tables from doing this.

Regards,

Bill

[Former Member]

Interestingly this wasn't our problem, it got resolved by .

The ACTIVE_TABLES table had a corrupted delta and mergedog would try to merge it around 15 minutes after startup. At this point the indexserver would restart.

Lloyd found it by starting the indexserver in console mode and watching the logs. He then copied the affected table, deleted the original and copied it back.

Then it was fine. Thanks for the reply.

[Former Member]

Hi Bill,

In case you find the reason behind the crash, request you to please share the findings for future reference.

Thanks & Regards,

Rahul Rajagopalan Nair

[Former Member]

Hi Bill,

Any details on the index server trace?

If you have a recent backup, the fastest way to get you db back up and running is indeed a fresh HANA One instance into which you restore the backup. 20 minutes and you're back online... But maybe you want to investigate the root cause for the crash...

Btw, the support forum for the production instances of HANA One is on http://www.saphana.com/community/solutions/cloud-info/cloud/hana-platform-aws, so it might be a good idea to cross-post you 911 there.

Cheers

--Juergen

[Former Member]

Hi Juergen & Rahul,

    I'm been busy getting my new instance up and running. Here are the trace specifics from indexserver_alert_hanaserver.trc:

[3084]{0}[0] 2013-01-17 19:45:09.598506 e Metadata     ptl_shm.cc(00520) : ShmSystem::attach (shmid=12550492, align=67108864) - Cannot allocate memory

[3084]{0}[0] 2013-01-17 19:45:09.599115 e Row_Engine   msglog.cc(00088) : Error during RowStore recovery: transaction rolled back due to unavailable resource (at ptime/storage/recovery/CheckpointMgr.cc:535 )

[3084]{0}[0] 2013-01-17 19:45:09.599273 e Basis        Crash.cpp(00558) : Crash at /HDB/IMP/NewDB100_REL/src///sys/src/Basis/Diagnose/impl/FaultProtectionImpl.cpp:531

Reason:

exception  1: no.2100002  (Basis/Diagnose/impl/FaultProtectionImpl.cpp:531)

    Illegal call to exit(), _exit() or _Exit() detected

exception throw location:

1: 0x00007f573f5b1f6a in exit_handler+0x46 at FaultProtectionImpl.cpp:531 (libhdbbasis.so)

2: 0x0000000000542bba in _exit+0x16 at LinuxMallocInitializer.cpp:143 (hdbindexserver)

3: 0x00007f5735f55897 in ptime::CheckpointMgr::restarter(void*)+0xd3 at CheckpointMgr.cc:536 (libhdbrskernel.so)

4: 0x00007f57354e9a00 in ptime::PtimeThread::run(void*)+0x10 at ptime_thread.h:131 (libhdbrskernel.so)

5: 0x00007f574c16c000 in TrexThreads::PoolThread::run()+0xc30 at PoolThread.cpp:255 (libhdbbasement.so)

6: 0x00007f574c16d7a8 in TrexThreads::PoolThread::run(void*&)+0x14 at PoolThread.cpp:104 (libhdbbasement.so)

7: 0x00007f573f641545 in Execution::Thread::staticMainImp(void**)+0x671 at Thread.cpp:448 (libhdbbasis.so)

8: 0x00007f573f64170d in Execution::Thread::staticMain(void*)+0x39 at Thread.cpp:512 (libhdbbasis.so)

[3084]{0}[0] 2013-01-17 19:45:09.645464 e Basis        FaultProtectionImpl.cpp(00961) : SIGNAL 6 (SIGABRT) caught, sender PID:  3042, PID: 3042, thread: 2710[thr=3084]: Checkpointer, value int: 464540312, ptr: 0xffff880f1bb05298, time: 2013-01-17 19:45:09 000 Local

Instance HDB/00, OS Linux hanaserver 2.6.32.27-0.2-default #1 SMP 2010-12-29 15:03:02 +0100 x86_64

The scenario occurred when I was attempting to load up my test database with approx 30GB of data into ROW tables on the 63 GB instance of HANA One. The import of two of the tables took forever, so I stopped the instance and restarted it. I then learned about ALTER SYSTEM LOGGING OFF; However, the damage was done. I believe that I managed to get too much data into the ROW tables and HANA ran out of memory. Here are the size of the data files for the database:

hanaserver:/hanadata/HDB/data/mnt00001> ls -l ./hdb00001                                                                                                                                                      

total 24668

-rw------- 1 hdbadm sapsys 335577088 2013-01-17 22:43 datavolume_0000.dat

-rw-rw-r-- 1 hdbadm sapsys        36 2013-01-17 19:43 landscape.id

hanaserver:/hanadata/HDB/data/mnt00001> ls -l ./hdb00002                                                                                                                                                      

total 34172160

-rw------- 1 hdbadm sapsys 35130195968 2013-01-16 02:48 datavolume_0000.dat

hanaserver:/hanadata/HDB/data/mnt00001> ls -l ./hdb00003                                                                                                                                                      

total 96152

-rw------- 1 hdbadm sapsys 351059968 2013-01-16 02:03 datavolume_0000.dat

hanaserver:/hanadata/HDB/data/mnt00001> ls -l ./hdb00004                                                                                                                                                      

total 26444

-rw------- 1 hdbadm sapsys 271745024 2013-01-16 02:03 datavolume_0000.dat

The instance seems to be running, but the SapService isn't running so HANA Studio can connect to even get the diagnostic traces. I have to go to Linux. I say this because when I issue the ./HDB stop command, it takes about 6 minutes to shut down.

Is there any way to delete tables or truncate tables in a database so that I can recover it?

Thanks,

Bill