Presented by,MySQL AB® &

O’Reilly Media, Inc.

Best Practices For Deploying MySQL on Solaris

Ritu KambojJenny Chen

Agenda

MySQL -Solaris Integration MySQL High Availability Data Service Consolidate MySQL Deployment Using Solaris

Containers DTrace (Jenny Chen)

MySQL-Solaris Integration

Optimized MySQL on Open Solaris

MySQL 5.0.45 (32bit) integrated with Open Solaris build 76 SXDE 01/08

MySQL 5.0.45 (64bit) integrated with Open Solaris build 87 SXCE

Layout of MySQL on Open Solaris

MySQL 5.0.45 packages Default data directory

/var/mysql/5.0/data Default configuration directory

/etc/mysql/5.0 Installation directory

/usr/mysql/5.0/

Latest version accessible from /usr/mysql/bin Symbolic link from all directories involved in 5.0.45 release to corresponding /usr/mysql

Optimization Of MySQL On Open Solaris

Compiled with optimal compiler options using Sun Studio compilers

Added SMF support for MySQL Easily accommodates varying configurations Initializes MySQL database thereby enhancing user experience Mysql user can manage MySQL database via SMF

Support for MySQL cluster engine (ndb)

Compiler Optimization

Enable in-lining Change header file univ.i to add Sun Studio

If (!defined(SUNPRO_C) #define UNIV_MUST_NOT_INLINE

Enable pre-fetching -xprefetch=auto and -xprefetch_level=3

Set optimization level -xO4

Compiler Optimization (Contd)

Feedback optimization (not yet implemented) Workload is key -xprofile -xipo Interprocess optimization About 10% improvement

Link with libmtmalloc Library for threaded application About 8% improvement

Service Management Facility (SMF)

Makes Solaris Services Self-Healing Services automatically restart in dependency

order Misbehaving and mis-configured services are

easier to debug Log files for each service

Administrators can securely delegate tasks to non-root users

MySQL-Service Management Facility

Dynamically configured properties mysql/bin

Installation , default : /usr/mysql/5.0/bin mysql/data

Data Directory , Default: /var/mysql/5.0/data mysql/enable_64bit

Flag to select 32bit or 64bit , Default : false

First time installations Creates system tables (mysql_install_db.sh )

Starting MySQL on Open Solaris

Older Open Solaris Build (Build 76- Build-87) 32Bit MySQL integrated Create mysql user Enable MySQL SMF service

Latest Open Solaris Build (Build 87 onwards) 32Bit and 64bit MySQL integrated Default mode : 32bit service For starting 64bit

Set enable_64bit == true

Optimized MySQL on Solaris 10

CoolStack SAMP stack + more

Optimized MySQL download Standalone package SAMP stack component

Available at Sun Download center: http://cooltools.sunsource.net/coolstack

Version MySQL 5.0.45 Similar optimizations as in Open Solaris

MySQL-High Availability Data Service

Solaris Cluster Overview Provides general purpose HA platform

Fifty percent of enterprises that lack arecovery plan go out of business

within one year of a significant disaster

Gartner Group

Availability is our customers' most critical requirement

Sun Cluster VOC Survey

Solaris Cluster : Hardware Components Servers with local storage

Can have up to 16 nodes Shared storage

Tolerates single-node failures Centralizes configuration files

Cluster interconnect At least two redundant networks

Public network interfaces Spreads outbound packets

Solaris Cluster Algorithms Cluster membership monitor

Ensures data integrity Determines cluster membership

Cluster configuration repository Global repository Ensures consistent view

Disk Fencing Fences off non-cluster nodes Prevents Partition

Quorum Uses a majority voting schema

MySQL High Availability Data Service HA-MySQL is a failover data service

Nod

e 1

Nod

e 2

Nod

e 3

Nod

e 4

DDBB

MySQL High Availability Data Service Supported configurations

Standalone MySQL server MySQL replication server

Single/Multiple MySQL instances in master configuration

Single/Multiple MySQL instances in slave configuration

Solaris containers supportGlobal zone Non-global failover zone Non-global zone

HA-MySQL Service Deployment

Node1 Node2:Zone2Node1:Zone1

Node2

MySQL

Stor Host

MySQL

Stor Host

MySQL-Solaris Cluster Benefits Enhanced end-to-end infrastructure availability Continuous MySQL Availability

Automatic failover if master node fails

Low cost solution Software is free and open sourced

Efficient Resource Utilization Multiple applications can be consolidated

Ease of operations SC enables clustered systems to be managed as if they were on a single system

Additional information

Step by step deployment guide http://docs.sun.com/app/docs/doc/819-3059

Failover study of HA-MySQL http://blogs.sun.com/krishs/date/200804

Solaris Cluster http://www.sun.com/software/solaris/cluster/index.xmlhttp://opensolaris.org/os/community/ha-clusters/

Consolidate MySQL installations using Solaris Containers

Solaris Containers Containers : Zones + Resource Management

Zones: isolated virtual application environments Resource management – resource control (CPU, Memory)

Achieving Consolidation Goals Reduce Hardware

Combine low utilization systems

Isolate applications from faults Maintain Service Levels

Fine tune response times

MySQL Consolidation Study System Configuration

Sun Fire X4100 (4 CPU, 8 GB Memory)

Local container configuration ( 1 CPU , 1 GB Memory

Sysbench Read-only Sysbench read-write

32 64 128 256

1300

1400

1500

1600

1700

1800

1900Sysbench read-only

No Containers

With Containers

Number of threads

Th

rou

gh

pu

t

32 64 128 256

0

100

200

300

400

500

600

700Sysbench read-write

No Containers

With Containers

Number of threads

Th

rou

gh

pu

t

Dtrace (Jenny Chen)

DTrace

Use DTrace with MySQL to drill down Monitoring MySQL Performance

Examples & Solutions

Easy Steps To add DTrace probes into MySQL core server and storage Engines

Easy Steps to display MySQL DTrace probes into Chime visualization Tool for DTrace

Why DTrace

Solaris 10 Dynamic Tracing Facility to provide comprehensive view of operating system and application behaviour

> DTrace to examine particular system areas: disk I/O, CPU, Memory

> Process Tracing and Debugging

USDT(User-level statically defined tracing) place custom probes in application code

Add USDT into MySQL source to monitor MySQL and gather the useful data missing by the current MySQL monitor tools:

DTrace: Monitor I/Os Exam I/O wait time by filename and mysqld(Available at DTraceToolkit)

#!/usr/sbin/dtrace –s

#pragma D option quiet

io:::wait-start

/ execname == “mysqld” /

{ self->start = timestamp; }

io:::wait-done

/ execname == “mysqld” && self->start /

{ this->elapsed = timestamp - self->start;

@files[pid,args[1]->dev_pathname, args[2]->fi_pathname] = sum(this->elapsed);

self->start = 0;

}

profile:::tick-5s

{ printf(“-------------------------------------------------\n”);

printf(“%6s %8s %20s %50s\n”, “PID”, “TIME”, “DEVICE”, “FILE”);

printa(“%6d %@8d %20s %8s \n”, @files);

printf (“------------------------------------------------\n”); }

#./mysqliowait.d

---------------------------------------------------

PID TIME DEVICE FILE

113 234 /dev/dsk/c0t2d0s0 /usr/local/mysql/data/ibdata1

DTrace: Monitor CPU classic performance problem

#!/usr/sbin/dtrace -s#pragma D option quietsyscall:::entry{

self->ts=vtimestamp;}syscall:::return/self->ts/{

@a[execname, probefunc] = count(); @b[execname, probefunc] = sum (vtimestamp - self->ts); self->ts=0;}END {

printf("%-16s %-16s %-8s\n","EXEC","SYSCALL","COUNT"); printa("%-16s %-16s %-@8d\n",@a); printf("%-16s %-16s %-8s\n","EXEC","SYSCALL","TIME"); printa("%-16s %-16s %-@8d\n",@b);

}

# ./syscall.d EXEC SYSCALL COUNT devfsadm lwp_park 1 dtrace fstat 1 ... mysqld read 106542 mysqld gtime 109613 mysqld pread 1181669 --------------------------------------------------- EXEC SYSCALL TIME dtrace lwp_sigmask 218 pkill getpid 302 ... mysqld read 259284183 mysqld write 267556239 mysqld pread 4650457224

Agrregated user stack backtrace to understand of the nature of pread() in MySQL source code – useful for mysql developers

# dtrace -n 'syscall::pread:entry / execname == "mysqld" / { @[ustack()]=count() } dtrace: description 'syscall::pread:entry ' matched 1 probe ... libc.so.1`_pread+0xa mysqld`my_pread+0x54 mysqld`_mi_read_static_record+0x67 mysqld`mi_rnext+0x1fe ... mysqld`handle_one_connection+0x855 libc.so.1`_thr_setup+0x67 1564811 .... Replace high cost pread with “--myisam_use_mmap=1”- useful for mysql DBA

A 94% performance improvement !

Dtrace: Memory Analysis Check which process causes anonymous page in

# dtrace -n anonpgin '{@[execname] = count()}' dtrace: description anonpgin matched 1 probe sshd 2 vmstat 23 mysqld 673

Use Dtrace to measure waiting for paging in# ./ whospaging.d – available at Solaris Internals(http://www.solarisinternals.com/si/dtrace/) Who's on cpu (milliseconds): sshd 1 vmstat 3 mysqld 120 sched 43210Who's waiting for pagin (milliseconds): mysqld 239082

Dtrace Probes In MySQL Provide deep view of internal MySQL core server and storage engines'

operation & behaviour>Database information>Query execution latency>Index & table scan cost>Wait events inside MyISAM & Innodb>Deadlock information>Query cache hit/miss>And many more...

Speed resolution of performance bottlenecks with in database design and MySQL server configurations

Negligible performance overhead

Easy steps to create & insert your own Dtrace probes into MySQL

MySQL DTrace GUI Monitor Tool - Chime

Query execution Time

Enable Slow query log with “–log-slow-queries” requires re-start MySQL server

SQL statements with query execution time longer than “long_query_time” second in the log file

SQL statements generating most loads on the application may not in slow query log

Replication query statements are not available in slow query log

Time spending by the query optimizer to generate query plan is not available in slow query log

Using DTrace can get mising query execution information online

Insert DTrace Probes Into MySQL

Step 1: Figure out what probes are needed to insert into the source code

Step 2: Define MySQL Provider and probes

# cat mysql_dtrace.d

provider mysql

{

probe query__execute__start(void *, char *, char *, const char *, char *);

probe query__execute__finish(void *, char *, char *, const char *, char *,int);

}

>Two Probes defined in the mysql provider>Note to use two underscore(__) translated to hypen automatically

Step 3: Define a header file “mysql_dtrace.h” with definitions for probes

dtrace -h -s mysql_dtrace.d

#ifndef _MYSQL_H

#define _MYSQL_H

#define DTRACE_QUERY_EXECUTE_START(arg0, arg1, arg2, arg3, arg4) \

__dtrace_mysql___query__execute__start(arg0, arg1, arg2, arg3, arg4)

#define DTRACE_QUERY_EXECUTE_START_ENABLED() \

__dtraceenabled_mysql___query__execute__start()

extern void __dtrace_mysql___query__execute__start(void *, char *, char *, char *, char *);

extern int __dtraceenabled_mysql___query__execute__start(void);

#endif

Step 4: Insert the probes into source code #include <mysql_dtrace.h>

...

bool mysql_execute_command(THD *thd)

{

DTRACE_QUERY_EXECUTE_START((void *)thd, thd->db,

thd->security_ctx->user, (char *)thd->security_ctx->host_or_ip,thd->query);

...

DTRACE_QUERY_EXECUTE_FINISH((void*)thd, thd->db,

thd->security_ctx->user, (char *)thd->security_ctx->host_or_ip,

thd->query, res ==0 ? 0: -1);

go to end;

...

}

Step 5: Build MySQL with DTrace In the Makefile.in, compile 64-bit MySQL with Dtrace

mysqld_OBJECTS = $(am_mysqld_OBJECTS) mysql_dtrace.$(OBJEXT)

mysql_dtrace.o:$(top_srcdir)/include/mysql_dtrace.d $(am_mysqld_OBJECTS)

dtrace -G 64 -s $(top_srcdir)/include/mysql_dtrace.d $(am_mysqld_OBJECTS)

Inserting DTrace probes comleted, DTrace probes are ready to use!

Step 6: Use inserted DTrace probes to measure query execution time with other database information #!/usr/sbin/dtrace -s

…

mysql*:::query-execute-start

{ self->start = timestamp; }

mysql*:::query-execute-finish

/self->start/

{ this->query = copyinstr(arg4); }

mysql*:::query-execute-finish

/self->start/

{ this->elapsed = (timestamp - self->start) / 1000000;

this->who = strjoin(copyinstr(arg2), strjoin("@", copyinstr(arg3)));

printf(" %-16.16s %-18.18s %5d %3d %-32.32s\n", arg1 ? copyinstr(arg1)

: ".", this->who, this->elapsed, (int)arg5, this->query); self->start = 0;

}

# ./mysqld_qestat.d

DATABASE USER@HOST ms RET QUERY

sbtest root@localhost 0 0 show tables

sbtest root@localhost 0 0 show databases sbtest root@localhost 178 0 select * from sbtest

Use the same steps to insert Dtrace probes to <source_tree>/sql/sql_select.cc at the start and end of choose_plan() function to measure the time spent in query optimization

optimizer_prune_level=1 reduce query compilation time Reduce optimizer_search_depth or optimizer_search_depth=0

Index & Table scan cost

Identify the places in MySQL source to handle scanning index, and table>Index-scan functions: index_next, index_next_same, index_prev, index_first, index_last>Table-scan functions: rnd_init, rnd_end, rnd_next, rnd_pos>Insert DTrace Probes at the start and before return from the functions can measure the time spending on scanning table or index.

mysql*:::innodb-index-next-start

{ @indexnext[args[0]] = count();

self->inext = timestamp; }

mysql*:::innodb-index-next-finish

/self->inext/

{ @indexnexttime[args[0]] = sum(timestamp - self->inext);

self->inext = 0; }

Expensive index-scan/table-scan report from Dtrace requires to optimize schema accordingly

Buffer wait in Innodb Innodb buffer wait is common in I/O-bound MySQL system while reading

page synchronous from disk Insert Dtrace probes at: innobase/buf/buf0rea.c,

ulint buf_read_page( ulint space, ulint offset) { ... DTRACE_INNODB_BUFFER_WAIT_START(); /* We do the i/o in the synchronous aio mode to save thread switches: hence TRUE */ count2 = buf_read_page_low(&err, TRUE, BUF_READ_ANY_PAGE, space, tablespace_version, offset); DTRACE_INNODB_BUFFER_WAIT_FINISH(); ... }

Increase innodb_buffer_pool size Tune SQL to access rows with fewer block reads(i.e. By adding indexes)

Query cache probes

Use DTrace to measure query cache hit and query cache miss to determine how well the query cache is performing

> Insert DTrace Probes at: sql/sql_cache.cc function: send_result_to_client

> DTrace Test script to report query cache hit and miss counts by query string, and totals

mysql*:::query-cache-hit,

mysql*:::query-cache-miss

{ this->query = copyinstr(arg4); }

mysql*:::query-cache-hit

{ @elapsed[this->query, "hit"] = count();

hits++; }

mysql*:::query-cache-miss

{ @elapsed[this->query, "miss"] = count();

misses++; }

# ./mysqld_qchit.d

Tracing... Hit Ctrl-C to end.

^C

QUERY RESULT COUNT

select * from months miss 1

select * from months where num > 3 hit 1

select * from months where num > 3 and num < 9 miss 1

show databases miss 1

show tables miss 1

select * from months hit 9

Hits : 10

Misses : 4

Hit Rate : 71%

Tuning “query_cache_size” variable according to the hit/miss rate

DTrace Performance Impact

Inserting DTrace Probes into MySQL source code are useful for MySQL DBA, MySQL & application developers. The performance impact of adding DTrace probes is critical for enterprise environment.

Cost of inserting USDT probe can be basically negligible: Each probe inserted into the source code can be enabled by adding the code like:

if (PROVIDER_PROBE_ENABLED() { PROVIDER_PROBE(arg0,...); }

DTrace Probes In MySQL 6.0

probe insert_row_start();probe insert_row_end();probe filesort_start();probe filesort_end();probe delete_start();probe delete_end();probe select_start()probe select_end();probe update_start();probe update_end();

compile with “--enable-dtrace” configure option to use the Dtrace probes

Integrate with Chime Tool Chime is graphical tool for visualizing DTrace aggregations. It

provides alternative CLI-based tool output with more visually

apprealing and more useful to display data over time

Available to download: http://www.opensolaris.org/os/project/dtrace-chime. One-step installation:

> Run pkgadd -d osol0chime-<arch>-1.4.pkg

chime requires Solaris Nevada build 35 or later

> Run local: /opt/OSOL0chime/bin/chime

> Run remotely: /opt/OSOL0chime/bin/chime <hostname>

chime provides wizard to automatically generate new display for DTrace script

Resources > http://www.opensolaris.org/os/community/dtrace - OpenSolaris Community: Dtrace > http://developers.sun.com/solaris/articles/solaris_perftools.html - Solaris Performance and Tools > http://docs.sun.com/app/docs/doc/817-6223/6mlkidlms?a=view - Statically Defined Tracing for User Applications chapter of DTrace Manual > http://www.brendangregg.com - DTrace toolkits > http://www.solarisinternals.com/wiki/index.php/DTrace_Topics_Databases - DTrace Topics Databases Acknowledgements Brandan Gregg – Sun Microsystems Engineer in Advanced Products Group