IM-B391 Agenda Getting Metrics Out From Database Servers

Extending System Center Monitoring to 3rd party Database EnginesOleg NoskovSoftware Architect, BridgeWays

IM-B391

Agenda

Building Database Management Packs

Common Critical Database Metrics

Common Oracle RAC Metrics

Best Practices on Management Packs

System Center Databases

Getting Metrics Out From Database ServersMost common - a SCOM agent based model

Has advantage of allowing remediation via SCOM Tasks

1-3% of incremental CPU usage when active

C/C++Provider ListenerPlatform Dependent

Client Libraries

MP Component Overview Simplified

Rules Views

Monitors

Tasks KB Reports

Management Pack

Management Server

RunAs Action Account

RunAs Privileged Account

C/C++ Provider

OM Agent

C/C++ Provider

OM Agent

OM AgentC/C++

Provider

OM Agent

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Database RunAs Accounts

RunAs Privileged Account RunAs Action Account

Only needed for UNIX/Linux database hosts.

Needed for all databases including those running on a Windows OS.

Provide root access to the monitored Oracle Database hosts.

Requires a minimum set of privileges in order to connect to the database instance and retrieve the necessary performance data

For root-level tasks, such as the tasks used to install and configure the Provider.

Database Privileges As Needed Only

Oracle Example – Actual List About 3 Times Longer

Table Privilege Table Privilege

V_$INSTANCE select V_$PARAMETER select

V_$TABLESPACE select V_$DATAFILE select

V_$SGASTAT select V_$TEMP_SPACE_HEADER

select

V_$SESSION select V_$LOCKED_OBJECT select

Test Your Management Pack Across All Platforms and Application Versions

MP

App V2

App V1

Plat 10

Plat 1

Plat 10

Plat 1

32-bit

64-bit

32-bit

64-bit

OM 2007

OM 2012

OM 2007

OM 2012

2 20 40 80Test

Environments

Video – RunAs Accounts & Provider Deployment

Best Practice Metrics Guidelines

Easy to collect

Easy to understand

Relevant to your system

Sensitive, but not too sensitive

Where Are The Metrics?!

All modern databases have “shadow” or system tables

Most (but not all) metrics can be retrieved from these tables

v$tables in Oracle

snapshots in DB2

sysmaster in Informix

“informational schema” tables in MySQL

Metrics #1

Know your baseline

Total number of commits

Total number of rollbacks

Exampleselect value from v$sysstat where name = 'user rollbacks'

select value from v$sysstat where name = 'user commits'

Metrics #2

Buffer Cache Hit Ratio

How efficient are my database transactions?

Exampleselect round((1 - ((P3.value) / (P2.value + P1.value)))*100, P3.value "FROM v$sysstat P1, v$sysstat P2, v$sysstat P3 WHERE P1.name = 'db block gets' AND P2.name = 'consistent gets' AND P3.name = 'physical reads'

Metrics #3

Is my index effective?

How often is a key found in the index?

Index may or may not need to be rebuilt

Exampleselect v$sysstat.value from v$sysstat, v$statname where v$sysstat.statistic# = v$statname.statistic# and v$statname.name in ('index fast full scans (full)','index fetch by key')

Metrics #4

Memory Sort vs Disk Sort

Ideally, you always want memory sorts

May need to tune the SQL to reduce the size of the sort to achieve optimal performance

Exampleselect v$sysstat.value from v$sysstat, v$statname where v$sysstat.statistic# = v$statname.statistic# and v$statname.name in ('sorts (disk)', 'sorts (memory)')

Metrics #5

Excessive Lock Wait Times

Often translates to poor performance

Exampleselect count(*) from v$session where lockwait is not null

SELECT eq_type "Lock",total_req# "Gets", total_wait# "Waits", cum_wait_time , (total_wait# / cum_wait_time ) * 100 from V$enqueue_stat WHERE Total_wait# > 0 and cum_wait_time <> 0

Metrics #6

Deadlocks

Relatively rare in production but still needs to be monitored.

Exampleselect name, value from v$sysstat where name = 'enqueue deadlocks'

Metrics #7

Large Table Scans

Tuning opportunity – may need an index

Exampleselect * from v$sql_plan p,v$sqlstat s,v$snapshot ss, DBA_SEGMENTS sg where p.object_owner <> 'SYS' and p.object_owner = sg.owner and p.object_name = sg.segment_name and sg.blocks > 1000 and p.operation like '%TABLE ACCESS%' and p.options like '%FULL%' and p.sql_id = s.sql_id and s.snap_id = ss.snap_id)

Metrics #8

High cursor count

Usually means a programmatic error with some applications

Exampleselect sum(a.value) as open_cursors from v$sesstat a , v$statname b where a.statistic# = b.statistic# and b.name = 'opened cursors current'

Metrics #9

Table size usage

Most commonly tracked metrics

Exampleselect TABLESPACE_NAME, round( USED_PERCENT, 2) from DBA_TABLESPACE_USAGE_METRICS

select b.tablespace_name OracleTablespace, round(nvl(a.bytes,0)/1024/1024) TotalMB, round(nvl(a.free,0)/1024/1024) FreeMB, round(nvl((a.bytes - free),0)/1024/1024) UsedMB, round((1 - (nvl(a.free/a.bytes,0))) * 100) UsedPct, round((nvl(a.free/a.bytes,0)) * 100) freePct, b.status, b.contents, b.segment_space_management, b.extent_management, decode(a.auto, 1, 'YES', 'NO') autoextensible from ( select f.tablespace_name tablespace_name, sum(nvl(f.bytes,0)) bytes, sum(decode(f.AUTOEXTENSIBLE,'YES',1,0)) auto, ( select sum(nvl(bytes,0)) from dba_free_space where f.tablespace_name = tablespace_name ) free from dba_data_files f group by f.tablespace_name union select t.tablespace_name tablespace_name, sum(nvl(t.bytes,0)) bytes, sum(decode(t.AUTOEXTENSIBLE,'YES',1,0)) auto,(select sum(nvl(bytes_free,0)) from v$temp_space_header where t.tablespace_name = tablespace_name ) freefrom dba_temp_files t group by t.tablespace_name a, dba_tablespaces b where a.tablespace_name = b.tablespace_name;

Metrics #10

Your database’s host metrics are just as important!!!

Virtual vs Physical

Your OS performance counters may not be reliable at all

DBA Configures VM With Somehow Gets Deployed with Memory Limits (IT Silos)

16 GB memory for optimal performance

8 GB

OS sees and thinks it has 16 GB Actually running out of memory and suffering with only 8GB

Demo - Examining Oracle, DB2, Informix, MySQL MetricsOleg Noskov

Oracle RAC

What is Oracle RAC?

An active active cluster

Database on shared storage

Cache Fusion

. . . . .

.

Node 1 Node n

High Speed Interconnect

SAN SAN

Oracle Instance

Oracle Instance

Client connecting in via virtual IP address

Local Cache

Local Cache

Oracle RAC Metrics #1

Global Cache Latency

Less than 2 msec ideally and no more than 15 msec

Consistent Read Blocks Received

Current Blocks Received

Consistent Read Block Latency (in msec) = (cr block receive time X 10) / (cr blocks received)

Current Block Latency (in msec) = (current block receive time X 10) / (current blocks received)


Global Enqueue Service (GES) Workload

GES manages all the non-Cache Fusion intra-instance and inter-instance resource operations.

High GES workload request rates can adversely affect performance.

Usually means a programmatic error with some applications


Balanced Workload Among Nodes

CPU, Memory, I/O, Network

Easily covered by Operation Manager (Windows, Linux, or UNIX)

Build unified monitor to alert when consistent unbalanced loads happen

Demo – Examining Oracle RAC Metrics

Oleg Noskov

More Best Practices on Management Packs

Management Pack Lifecycle Management

Demo – Management Pack Lifecycle

Randy Roffey

System Center Databases

What to look for?

Demo – System Center Databases

Randy Roffey

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Complete your session evaluations today and enter to win prizes daily. Provide your feedback at a CommNet kiosk or log on at www.2013mms.com.Upon submission you will receive instant notification if you have won a prize. Prize pickup is at the Information Desk located in Attendee Services in the Mandalay Bay Foyer. Entry details can be found on the MMS website.

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IM-B391 Agenda Getting Metrics Out From Database Servers