Presented by, MySQL AB® & OReilly Media, Inc. Best Practices For Deploying MySQL on Solaris Ritu Kamboj Jenny 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 (32bit) integrated with Open Solaris build 76 SXDE 01/08 MySQL (64bit) integrated with Open Solaris build 87 SXCE

Layout of MySQL on Open Solaris MySQL 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 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: Version MySQL 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 a recovery 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 Node 1 Node 2 Node 3 Node 4 DBDBDBDB

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 support Global zone Non-global failover zone Non-global zone

HA-MySQL Service Deployment Node1Node2:Zone2 Node1:Zone1 Node2 MySQL StorHost MySQL StorHost

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 Failover study of HA-MySQL Solaris Cluster

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

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 - 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 %20s %8s printf ( \n); } #./mysqliowait.d PID TIMEDEVICE FILE /dev/dsk/c0t2d0s0 /usr/local/mysql/data/ibdata1

DTrace: Monitor CPU classic performance problem #!/usr/sbin/dtrace -s #pragma D option quiet syscall:::entry { self->ts=vtimestamp; } syscall:::return /self->ts/ probefunc] = probefunc] = sum (vtimestamp - self->ts); self->ts=0; } END { printf("%-16s %-16s %-8s\n","EXEC","SYSCALL","COUNT"); printa("%-16s %-16s printf("%-16s %-16s %-8s\n","EXEC","SYSCALL","TIME"); printa("%-16s %-16s }

#./syscall.d EXEC SYSCALL COUNT devfsadm lwp_park 1 dtrace fstat 1... mysqld read mysqld gtime mysqld pread EXEC SYSCALL TIME dtrace lwp_sigmask 218 pkill getpid mysqld read mysqld write mysqld pread

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" / } 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+0x 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 = 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( Who's on cpu (milliseconds): sshd 1 vmstat 3 mysqld 120 sched43210 Who's waiting for pagin (milliseconds): mysqld239082

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... 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) / ; this->who = strjoin(copyinstr(arg2), 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 ms RET QUERY sbtest 0 0 show tables sbtest 0 0 show databases sbtest select * from sbtest Use the same steps to insert Dtrace probes to /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 = count(); self->inext = timestamp; } mysql*:::innodb-index-next-finish /self->inext/ = 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 "hit"] = count(); hits++; } mysql*:::query-cache- miss "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: One-step installation: > Run pkgadd -d osol0chime pkg chime requires Solaris Nevada build 35 or later > Run local: /opt/OSOL0chime/bin/chime > Run remotely: /opt/OSOL0chime/bin/chime chime provides wizard to automatically generate new display for DTrace script

Resources > - OpenSolaris Community: Dtrace > - Solaris Performance and Tools > - Statically Defined Tracing for User Applications chapter of DTrace Manual > - DTrace toolkits > - DTrace Topics Databases Acknowledgements Brandan Gregg – Sun Microsystems Engineer in Advanced Products Group