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Filesystem monitoring by NPS software

Starting from NPS version 7, we can now monitor Netezza mount points /nz and /nzscratch using the newly introduced system manager threshold parameters. These parameters can be defined in /nz/data/config/system.cfg

1) sysmgr.hostFileSystemUsageThresholdOneToRiseEvent (default value is 85%)
This parameter will send a notification when ever /nz or /nzscratch filesystem (mount point) usage goes above 85%.

2) sysmgr.hostFileSystemUsageThresholdTwoToRiseEvent (default value is 90%)
This parameter will send a warning message when ever /nz or /nzscratch filesystem (mount point) usage goes above 90%.

3) sysmgr.hostFileSystemUsageThresholdToStopSystem (default value is 95%)
This parameter will stop Netezza if /nz or /nzscratch usgae goes above 95% (for NPS version 7.0.0, 7.0.1 and 7.0.2). Starting from v7.0.3 system stops Netezza only if /nz file system is 95% full and not for /nzscratch.

All these parameters can take any value between 1 to 100, in percentage.

Script to list out all the SQL Server logins

Script to list out all the SQL Server logins along with its properties. The output of this script will be a create login script which can be run on the target machine where all these logins are to be migrated.
You will see their are two selct queries in this script. First select query is to pull out all the SQL authenticated logins and second script will pull out all the Windows authenticated logins.

SELECT ‘CREATE LOGIN ‘ + QUOTENAME(name) + ‘ WITH PASSWORD=’
+ sys.fn_varbintohexstr(password_hash) + ‘ HASHED, SID=’
+ sys.fn_varbintohexstr(sid) + ‘, ‘
+ ‘DEFAULT_DATABASE=’+ QUOTENAME(COALESCE(default_database_name, ‘master’))
+ ‘, DEFAULT_LANGUAGE=’ + QUOTENAME(COALESCE(default_language_name, ‘us_english’))
+ ‘, CHECK_EXPIRATION=’ + CASE is_expiration_checked WHEN 1 THEN ‘ON’ ELSE
‘OFF’ END
+ ‘, CHECK_POLICY=’ + CASE is_policy_checked WHEN 1 THEN ‘ON’ ELSE ‘OFF’ END as ‘SQL Server Logins’
FROM sys.sql_logins
WHERE name not like ‘sa’
UNION ALL
SELECT ‘CREATE LOGIN ‘ + QUOTENAME(name) + ‘ FROM WINDOWS WITH ‘
+ ‘DEFAULT_DATABASE=’+ QUOTENAME(COALESCE(default_database_name, ‘master’))
+ ‘, DEFAULT_LANGUAGE=’ + QUOTENAME(COALESCE(default_language_name,
‘us_english’)) as ‘SQL Server Logins’
FROM sys.server_principals
WHERE type IN (‘U’,’G’)

[\sql]

ERROR: Recursion detected in view expansion

ISSUE:
You may see this error when trying to query a view or create a view on another view.

ERROR: Recursion detected in view expansion

CAUSE:
Possible issue is that your view is broken and is pointing to itself. Just generate a ddl of this view and you will find something like below i.e. a view pointing to itself.

create or replace view MyView1
as select * from MyView1

RESOLUTION:
Netezza do not allow creating a view pointing to itself or any object with same name in a database. But there is a bug in Netezza which allows you to create a view pointing to itself if view already exist.

To resolve the issue you have to recreate a view with correct defination for the query to run successfully.
MORE EXPLANATION:
1) If you create a brand new view pointing to itself you will get error:
TESTDB.ADMIN(ADMIN)=> create or replace view MyView1 as select * from MyView1;
ERROR: relation does not exist TESTDB.ADMIN.MYVIEW1

2) Now, if you create this view as valid view it will run fine:
TESTDB.ADMIN(ADMIN)=> create or replace view MyView1 as select * from T1;
CREATE VIEW

3) Run select on view and it will run fine:
TESTDB.ADMIN(ADMIN)=> select * from MyView1;
<Runs Successfully>

4) Now, again try to recreate this view as we tried to create in step 1. It will work fine:
TESTDB.ADMIN(ADMIN)=> create or replace view MyView1 as select * from MyView1;
CREATE VIEW

5) Run select on view and it will throw error:
TESTDB.ADMIN(ADMIN)=> select * from MyView1;
ERROR: Recursion detected in view expansion

 

 

Core files in Netezza

Core file is generated when for some reason Netezza is not able to process some requests and hit some issue which result in Netezza server to dump all the contents of memory to a file for diagnostics purpose.

Basic idea to identify what component generated a core file.
- If core file is generated at /nz/data or /nz/data.1.0 then this core file is probably generated by postmaster process.
- If core file is generated at /nz/kit/log/spucores then the core file is generated by SPU cores.
- If core file ise generated by any of the NPS server processes then the core file will be found under /nz/kit.5.0.6.P1/log/ and the respective process directory like /nz/kit.5.0.6.P1/log/dbos.

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.