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Netezza Thermal Fault Event – Known Bug

Issue:
Thermal fault warning by TwinFin Server running on NPS v 6.0.5P5
NzEv-diskEncl Thermal_Fault 1122 @ 1st Rack, 7th DiskEnclosure for ServerName at 06-Nov-13, 01:14:22 EST

Exact Event Text:
Hostname ServerName
NzEvents 1
Event Thermal_Fault
Event Time 06-Nov-13, 01:14:22 EST
hwType diskEncl
hwLocation 1st Rack, 7th DiskEnclosure label slot-3 hwId 1122 currentValue $curValue errString Temperature reading is in missing state eventSource System initiated

Cause:
This is a know bug in NPS v6 that can be ignored. It’s a temperature misread by the system and not a actual issue. Basically the system was trying to get the temp of the enclosure but at the same time the sensor is trying to get the temperature. Thus it hits this bug.

Resolution:
This is a know bug. No action needed.

screen command – Unix

If you are connected to you Netezza server remotely using Putty or similar tool and have to run large scripts which will return output to screen then you can make use of screen command so taht you can re-connect to the session incase your connection is lost.

$ screen myscript.sh

Now, if your connection is lost then you can reconnect to the lost sesison by logging in again to the system using same id and thne run below command.

$ screen -r

ERROR: 0 : Can’t parse input

ERROR: 0 : Can’t parse input

You get this error randomly. Queries some time work fine but fail some other time when using one of the SQL Extension toolkit functions. Possibly with different data set.

This error is recorded in postgres and dbos log:

Postgres Logs:
more pg.log | grep ERROR
pg.log.18:2013-11-01 11:12:06.793853 EDT [9902] ERROR: 0 : Can’t parse input

DBOS Logs:
more dbos.log | grep ERROR
planid 103419 tx 0x2dbe6ce cli 316 uid 60439 sid 75581 pid [17759] spu ID 180 err = 0 : Can’t parse input

Possible cause is the queries that make use of SQL extension toolkit functions like array_count, array_split, regexp_replace, etc. This is a known issue in version 1.4.
This random error is fixed in SQL extension toolkit version 1.6P2. If your current version is below 1.6P2 then upgrade to this version.

Distributed Replicated Block Device (DRBD) in Netezza

Distributed Replicated Block Device (DRBD) is a block device driver that can replicate disk, partition, blocks, etc across different Linus database hosts in a HA cluster environment. Here are some of the high-level details on how DRDB works in Netezza appliance.

  • Netezza uses DRBD to replicate /nz and /export/home mount points from active (primary) host to passive (secondary) host
  • Data on primary host is committed only when it is written to secondary host i.e. synchronous replication is used
  • Synchronous replication helps in avoiding data loss incase of failover
  • Read activity from above mount points always take place in active host
  • Never stop DRBD service until or unless recommended by Netezza support. NOTE: This can result in brain split. A condition when both the nodes will have different data image

How to check DRBD service ?

DRBD service status can be checked by using one of the below two methods:

  • Run “service drbd status” command in Unix host
  • Run “cat /proc/drbd” command in Unix host

How to find which all library files are missing for Netezza client to run fine?

To find which all library files are missing for Netezza client to run fine, you can just run the below command:

$ pwd
/nzhome/nzclient/v707

$ ldd ./bin/nzsql
linux-gate.so.1 => (0x009b0000)
libz.so.1 => /lib/libz.so.1 (0x004ca000)
libcrypt.so.1 => /lib/libcrypt.so.1 (0x001ba000)
libssl.so.6 => not found
libcrypto.so.6 => not found
libresolv.so.2 => /lib/libresolv.so.2 (0×00182000)
libnsl.so.1 => /lib/libnsl.so.1 (0x003e1000)
libdl.so.2 => /lib/libdl.so.2 (0x002ef000)
libncurses.so.5 => not found
libm.so.6 => /lib/libm.so.6 (0×00110000)
libc.so.6 => /lib/libc.so.6 (0x004de000)
libfreebl3.so => /lib/libfreebl3.so (0×00711000)
/lib/ld-linux.so.2 (0x0013b000)

Here you will find all the missing files. So you may have to make a symbolic links to these library files for NzClient to run fine.
Since, Netezza Client v707 (and older) are 32bit clients for Linux, so make sure you link 32 bit library files only.

NOTE: In above example client is installed at /nzhome/nzclient/v707
Below library packages may needs to be installed (if required library fles does not exist) in order to fix above issue.

1) libssl.so.6 is a soft link that you should created to /usr/lib/libssl.so.10. So if this library file does not exist then you may have to get below package installed from Linus admin.

openssl-1.0.0-20.el6.i686 : A general purpose cryptography library with TLS implementation
Repo : as6-u2_64
Matched from:
Filename : /usr/lib/.libssl.so.10.hmac
Other : libssl.so.10
Filename : /usr/lib/libssl.so.1.0.0
Filename : /usr/lib/libssl.so.10
Filename : /usr/lib/.libssl.so.1.0.0.hmac

2) libcrypto.so.6 is a soft link that you should created to /usr/lib/libcrypto.so.10. So if this library file does not exist then you may have to get below package installed from Linus admin

openssl-1.0.0-20.el6.i686 : A general purpose cryptography library with TLS implementation
Repo : as6-u2_64
Matched from:
Filename : /usr/lib/.libcrypto.so.10.hmac
Filename : /usr/lib/.libcrypto.so.1.0.0.hmac
Filename : /usr/lib/libcrypto.so.1.0.0
Other : libcrypto.so.10
Filename : /usr/lib/libcrypto.so.10

3) libncurses.so.5 is a soft link that you should created to /lib/libncurses.so.5. So if this library file does not exist then you may have to get below package installed from Linus admin

ncurses-libs-5.7-3.20090208.el6.i686 : Ncurses libraries
Repo : as6-u2_64
Matched from:
Filename : /lib/libncurses.so.5.7
Other : libncurses.so.5
Filename : /lib/libncurses.so.5