From c02b424af9b8cf30e3e13cbc555736f1626e3da3 Mon Sep 17 00:00:00 2001 From: AliSQL Date: Sat, 8 Oct 2016 11:03:30 +0800 Subject: [PATCH] Issue#9: PROVIDE ADAPTIVE ALGORITHM FOR INNODB CONCURRENCY TICKETS MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Description: ------------ To avoide too many concurrency threads，InnoDB use innodb_thread_concurrency to control the number of operating system threads concurrently inside InnoDB. When a thread is permitted to enter InnoDB, it is given a number of "free tickets" equal to the value of innodb_concurrency_tickets, and the thread can enter and leave InnoDB freely until it has used up its tickets. innodb_concurrency_tickets is a fixed number, and it is hard to choose a proper value fit for both small transactions and large transactons. With a small innodb_concurrency_tickets value, large transactons will acquire tickets many times, which extends the length of time required to complete their task. With a large innodb_concurrency_tickets value, small transactons may get starved by too many concurrent large transactions. This patch provides a method to adaptively adjust tickets assigned to readonly SELECT SQL statement. For large SELECT query, it may acquire tickets many times if the previous assigned tickets are exhausted. To avoid starving smally quries, the tickets assiged to large query are decreased exponentially according to the number of times it acquire tickets, i.e. the more times large query acquire tickets, the smaller tickets it will be assigned. To avoid it getting a too small value, innodb_rds_min_concurrency_tickets is used as the lower bound of the tickets number assigned. Two global InnoDB variables are added, 1. innodb_rds_adaptive_tickets_algo: control whether adaptive algorithm is enabled. 2. innodb_rds_min_concurrency_tickets: the lower bound of tickets can be assiged under adaptive adjusting. --- mysql-test/suite/rds/my.cnf | 8 ++ ...adaptive_concurrency_tickets_issue9.result | 87 +++++++++++++++++++ ...b_adaptive_concurrency_tickets_issue9.test | 49 +++++++++++ .../sys_vars/r/sysvars_innodb,32bit.rdiff | 53 ++++++----- .../suite/sys_vars/r/sysvars_innodb.result | 28 ++++++ storage/innobase/handler/ha_innodb.cc | 16 ++++ storage/innobase/include/srv0srv.h | 4 + storage/innobase/include/trx0trx.h | 8 ++ storage/innobase/srv/srv0conc.cc | 35 +++++++- storage/innobase/trx/trx0trx.cc | 2 + 10 files changed, 269 insertions(+), 21 deletions(-) create mode 100644 mysql-test/suite/rds/my.cnf create mode 100644 mysql-test/suite/rds/r/feature_innodb_adaptive_concurrency_tickets_issue9.result create mode 100644 mysql-test/suite/rds/t/feature_innodb_adaptive_concurrency_tickets_issue9.test diff --git a/mysql-test/suite/rds/my.cnf b/mysql-test/suite/rds/my.cnf new file mode 100644 index 00000000000..153639c67f8 --- /dev/null +++ b/mysql-test/suite/rds/my.cnf @@ -0,0 +1,8 @@ +# Use settings from rpl_1slave_base.cnf +# add setting to connect the slave to the master by default +!include ../rpl/rpl_1slave_base.cnf +!include include/default_client.cnf + + +[mysqld.2] + diff --git a/mysql-test/suite/rds/r/feature_innodb_adaptive_concurrency_tickets_issue9.result b/mysql-test/suite/rds/r/feature_innodb_adaptive_concurrency_tickets_issue9.result new file mode 100644 index 00000000000..1dd8359ea22 --- /dev/null +++ b/mysql-test/suite/rds/r/feature_innodb_adaptive_concurrency_tickets_issue9.result @@ -0,0 +1,87 @@ +SET @global_start_value1 = @@global.innodb_rds_adaptive_tickets_algo; +SELECT @global_start_value1; +@global_start_value1 +0 +SET @global_start_value2 = @@global.innodb_rds_min_concurrency_tickets; +SELECT @global_start_value2; +@global_start_value2 +50 +SET @global_start_value3 = @@global.innodb_thread_concurrency; +SELECT @global_start_value3; +@global_start_value3 +0 +SET @global_start_value4 = @@global.innodb_concurrency_tickets; +SELECT @global_start_value4; +@global_start_value4 +5000 +SET @global_start_value5 = @@global.innodb_thread_sleep_delay; +SELECT @global_start_value5; +@global_start_value5 +10000 +SET @@global.innodb_rds_adaptive_tickets_algo = TRUE; +SELECT @@global.innodb_rds_adaptive_tickets_algo; +@@global.innodb_rds_adaptive_tickets_algo +1 +SET @@global.innodb_rds_min_concurrency_tickets = 5; +SELECT @@global.innodb_rds_min_concurrency_tickets; +@@global.innodb_rds_min_concurrency_tickets +5 +SET @@global.innodb_thread_concurrency = 2; +SELECT @@global.innodb_thread_concurrency; +@@global.innodb_thread_concurrency +2 +SET @@global.innodb_concurrency_tickets=8; +create table t1(c1 int, c2 int) engine=innodb; +begin; +insert into t1 +values(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9),(10,10); +commit; +select * from t1; +c1 c2 +1 1 +2 2 +3 3 +4 4 +5 5 +6 6 +7 7 +8 8 +9 9 +10 10 +SET @@global.innodb_rds_adaptive_tickets_algo = FALSE; +SELECT @@global.innodb_rds_adaptive_tickets_algo; +@@global.innodb_rds_adaptive_tickets_algo +0 +select * from t1; +c1 c2 +1 1 +2 2 +3 3 +4 4 +5 5 +6 6 +7 7 +8 8 +9 9 +10 10 +drop table t1; +SET @@global.innodb_rds_adaptive_tickets_algo = @global_start_value1; +SELECT @global_start_value1; +@global_start_value1 +0 +SET @@global.innodb_rds_min_concurrency_tickets = @global_start_value2; +SELECT @global_start_value2; +@global_start_value2 +50 +SET @@global.innodb_thread_concurrency = @global_start_value3; +SELECT @global_start_value3; +@global_start_value3 +0 +SET @@global.innodb_concurrency_tickets= @global_start_value4; +SELECT @global_start_value4; +@global_start_value4 +5000 +SET @@global.innodb_thread_sleep_delay= @global_start_value5; +SELECT @global_start_value5; +@global_start_value5 +10000 diff --git a/mysql-test/suite/rds/t/feature_innodb_adaptive_concurrency_tickets_issue9.test b/mysql-test/suite/rds/t/feature_innodb_adaptive_concurrency_tickets_issue9.test new file mode 100644 index 00000000000..64dc4133416 --- /dev/null +++ b/mysql-test/suite/rds/t/feature_innodb_adaptive_concurrency_tickets_issue9.test @@ -0,0 +1,49 @@ +--source include/have_innodb.inc +--source include/load_sysvars.inc + +SET @global_start_value1 = @@global.innodb_rds_adaptive_tickets_algo; +SELECT @global_start_value1; +SET @global_start_value2 = @@global.innodb_rds_min_concurrency_tickets; +SELECT @global_start_value2; +SET @global_start_value3 = @@global.innodb_thread_concurrency; +SELECT @global_start_value3; +SET @global_start_value4 = @@global.innodb_concurrency_tickets; +SELECT @global_start_value4; +SET @global_start_value5 = @@global.innodb_thread_sleep_delay; +SELECT @global_start_value5; + +SET @@global.innodb_rds_adaptive_tickets_algo = TRUE; +SELECT @@global.innodb_rds_adaptive_tickets_algo; + +SET @@global.innodb_rds_min_concurrency_tickets = 5; +SELECT @@global.innodb_rds_min_concurrency_tickets; + +SET @@global.innodb_thread_concurrency = 2; +SELECT @@global.innodb_thread_concurrency; + +SET @@global.innodb_concurrency_tickets=8; + +create table t1(c1 int, c2 int) engine=innodb; +begin; +insert into t1 +values(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9),(10,10); +commit; + +select * from t1; + +SET @@global.innodb_rds_adaptive_tickets_algo = FALSE; +SELECT @@global.innodb_rds_adaptive_tickets_algo; + +select * from t1; + +drop table t1; +SET @@global.innodb_rds_adaptive_tickets_algo = @global_start_value1; +SELECT @global_start_value1; +SET @@global.innodb_rds_min_concurrency_tickets = @global_start_value2; +SELECT @global_start_value2; +SET @@global.innodb_thread_concurrency = @global_start_value3; +SELECT @global_start_value3; +SET @@global.innodb_concurrency_tickets= @global_start_value4; +SELECT @global_start_value4; +SET @@global.innodb_thread_sleep_delay= @global_start_value5; +SELECT @global_start_value5; diff --git a/mysql-test/suite/sys_vars/r/sysvars_innodb,32bit.rdiff b/mysql-test/suite/sys_vars/r/sysvars_innodb,32bit.rdiff index 09a0a918410..f3229117621 100644 --- a/mysql-test/suite/sys_vars/r/sysvars_innodb,32bit.rdiff +++ b/mysql-test/suite/sys_vars/r/sysvars_innodb,32bit.rdiff @@ -1,5 +1,5 @@ ---- suite/sys_vars/r/sysvars_innodb.result 2017-05-10 10:25:27.196836832 +0200 -+++ suite/sys_vars/r/sysvars_innodb.reject 2017-05-10 17:54:00.922046824 +0200 +--- sysvars_innodb.result ++++ sysvars_innodb.result @@ -54,7 +54,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 8 @@ -554,7 +554,20 @@ VARIABLE_COMMENT Purge threads can be from 1 to 32. Default is 4. NUMERIC_MIN_VALUE 1 NUMERIC_MAX_VALUE 32 -@@ -2322,7 +2322,7 @@ +@@ -2336,10 +2336,10 @@ + GLOBAL_VALUE_ORIGIN COMPILE-TIME + DEFAULT_VALUE 50 + VARIABLE_SCOPE GLOBAL +-VARIABLE_TYPE BIGINT UNSIGNED ++VARIABLE_TYPE INT UNSIGNED + VARIABLE_COMMENT The lower bound of the concurrency_tickets when rds_adaptive_tickets_algo is enabled + NUMERIC_MIN_VALUE 1 +-NUMERIC_MAX_VALUE 18446744073709551615 ++NUMERIC_MAX_VALUE 4294967295 + NUMERIC_BLOCK_SIZE 0 + ENUM_VALUE_LIST NULL + READ_ONLY NO +@@ -2350,7 +2350,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 56 VARIABLE_SCOPE GLOBAL @@ -563,7 +576,7 @@ VARIABLE_COMMENT Number of pages that must be accessed sequentially for InnoDB to trigger a readahead. NUMERIC_MIN_VALUE 0 NUMERIC_MAX_VALUE 64 -@@ -2336,7 +2336,7 @@ +@@ -2364,7 +2364,7 @@ GLOBAL_VALUE_ORIGIN CONFIG DEFAULT_VALUE 4 VARIABLE_SCOPE GLOBAL @@ -572,7 +585,7 @@ VARIABLE_COMMENT Number of background read I/O threads in InnoDB. NUMERIC_MIN_VALUE 1 NUMERIC_MAX_VALUE 64 -@@ -2364,10 +2364,10 @@ +@@ -2392,10 +2392,10 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 0 VARIABLE_SCOPE GLOBAL @@ -585,7 +598,7 @@ NUMERIC_BLOCK_SIZE 0 ENUM_VALUE_LIST NULL READ_ONLY NO -@@ -2392,7 +2392,7 @@ +@@ -2420,7 +2420,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 128 VARIABLE_SCOPE GLOBAL @@ -594,7 +607,7 @@ VARIABLE_COMMENT Number of undo logs to use (deprecated). NUMERIC_MIN_VALUE 1 NUMERIC_MAX_VALUE 128 -@@ -2420,7 +2420,7 @@ +@@ -2448,7 +2448,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 0 VARIABLE_SCOPE GLOBAL @@ -603,7 +616,7 @@ VARIABLE_COMMENT An InnoDB page number. NUMERIC_MIN_VALUE 0 NUMERIC_MAX_VALUE 4294967295 -@@ -2434,7 +2434,7 @@ +@@ -2462,7 +2462,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 0 VARIABLE_SCOPE GLOBAL @@ -612,7 +625,7 @@ VARIABLE_COMMENT Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions. NUMERIC_MIN_VALUE 0 NUMERIC_MAX_VALUE 39 -@@ -2448,7 +2448,7 @@ +@@ -2476,7 +2476,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 0 VARIABLE_SCOPE GLOBAL @@ -621,7 +634,7 @@ VARIABLE_COMMENT Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions. NUMERIC_MIN_VALUE 0 NUMERIC_MAX_VALUE 39 -@@ -2462,7 +2462,7 @@ +@@ -2490,7 +2490,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 0 VARIABLE_SCOPE GLOBAL @@ -630,7 +643,7 @@ VARIABLE_COMMENT Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions. NUMERIC_MIN_VALUE 0 NUMERIC_MAX_VALUE 39 -@@ -2504,7 +2504,7 @@ +@@ -2532,7 +2532,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 0 VARIABLE_SCOPE GLOBAL @@ -639,7 +652,7 @@ VARIABLE_COMMENT Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions. NUMERIC_MIN_VALUE 0 NUMERIC_MAX_VALUE 1000 -@@ -2518,7 +2518,7 @@ +@@ -2546,7 +2546,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 0 VARIABLE_SCOPE GLOBAL @@ -648,7 +661,7 @@ VARIABLE_COMMENT Deprecated and ignored; only exists to allow easier upgrade from earlier XtraDB versions. NUMERIC_MIN_VALUE 0 NUMERIC_MAX_VALUE 1 -@@ -2546,7 +2546,7 @@ +@@ -2574,7 +2574,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 1048576 VARIABLE_SCOPE GLOBAL @@ -657,7 +670,7 @@ VARIABLE_COMMENT Memory buffer size for index creation NUMERIC_MIN_VALUE 65536 NUMERIC_MAX_VALUE 67108864 -@@ -2770,7 +2770,7 @@ +@@ -2798,7 +2798,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 1 VARIABLE_SCOPE GLOBAL @@ -666,7 +679,7 @@ VARIABLE_COMMENT Size of the mutex/lock wait array. NUMERIC_MIN_VALUE 1 NUMERIC_MAX_VALUE 1024 -@@ -2798,10 +2798,10 @@ +@@ -2826,10 +2826,10 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 30 VARIABLE_SCOPE GLOBAL @@ -679,7 +692,7 @@ NUMERIC_BLOCK_SIZE 0 ENUM_VALUE_LIST NULL READ_ONLY NO -@@ -2840,7 +2840,7 @@ +@@ -2868,7 +2868,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 0 VARIABLE_SCOPE GLOBAL @@ -688,7 +701,7 @@ VARIABLE_COMMENT Helps in performance tuning in heavily concurrent environments. Sets the maximum number of threads allowed inside InnoDB. Value 0 will disable the thread throttling. NUMERIC_MIN_VALUE 0 NUMERIC_MAX_VALUE 1000 -@@ -2854,7 +2854,7 @@ +@@ -2882,7 +2882,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 10000 VARIABLE_SCOPE GLOBAL @@ -697,7 +710,7 @@ VARIABLE_COMMENT Time of innodb thread sleeping before joining InnoDB queue (usec). Value 0 disable a sleep NUMERIC_MIN_VALUE 0 NUMERIC_MAX_VALUE 1000000 -@@ -2952,7 +2952,7 @@ +@@ -2980,7 +2980,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 128 VARIABLE_SCOPE GLOBAL @@ -706,7 +719,7 @@ VARIABLE_COMMENT Number of undo logs to use. NUMERIC_MIN_VALUE 1 NUMERIC_MAX_VALUE 128 -@@ -2980,7 +2980,7 @@ +@@ -3008,7 +3008,7 @@ GLOBAL_VALUE_ORIGIN COMPILE-TIME DEFAULT_VALUE 0 VARIABLE_SCOPE GLOBAL @@ -715,7 +728,7 @@ VARIABLE_COMMENT Number of undo tablespaces to use. NUMERIC_MIN_VALUE 0 NUMERIC_MAX_VALUE 127 -@@ -3092,7 +3092,7 @@ +@@ -3120,7 +3120,7 @@ GLOBAL_VALUE_ORIGIN CONFIG DEFAULT_VALUE 4 VARIABLE_SCOPE GLOBAL diff --git a/mysql-test/suite/sys_vars/r/sysvars_innodb.result b/mysql-test/suite/sys_vars/r/sysvars_innodb.result index e9fc3693889..0fc4211eace 100644 --- a/mysql-test/suite/sys_vars/r/sysvars_innodb.result +++ b/mysql-test/suite/sys_vars/r/sysvars_innodb.result @@ -2316,6 +2316,34 @@ NUMERIC_BLOCK_SIZE NULL ENUM_VALUE_LIST OFF,ON READ_ONLY NO COMMAND_LINE_ARGUMENT NONE +VARIABLE_NAME INNODB_RDS_ADAPTIVE_TICKETS_ALGO +SESSION_VALUE NULL +GLOBAL_VALUE OFF +GLOBAL_VALUE_ORIGIN COMPILE-TIME +DEFAULT_VALUE OFF +VARIABLE_SCOPE GLOBAL +VARIABLE_TYPE BOOLEAN +VARIABLE_COMMENT Whether to enable the adaptive tickets algorithm +NUMERIC_MIN_VALUE NULL +NUMERIC_MAX_VALUE NULL +NUMERIC_BLOCK_SIZE NULL +ENUM_VALUE_LIST OFF,ON +READ_ONLY NO +COMMAND_LINE_ARGUMENT REQUIRED +VARIABLE_NAME INNODB_RDS_MIN_CONCURRENCY_TICKETS +SESSION_VALUE NULL +GLOBAL_VALUE 50 +GLOBAL_VALUE_ORIGIN COMPILE-TIME +DEFAULT_VALUE 50 +VARIABLE_SCOPE GLOBAL +VARIABLE_TYPE BIGINT UNSIGNED +VARIABLE_COMMENT The lower bound of the concurrency_tickets when rds_adaptive_tickets_algo is enabled +NUMERIC_MIN_VALUE 1 +NUMERIC_MAX_VALUE 18446744073709551615 +NUMERIC_BLOCK_SIZE 0 +ENUM_VALUE_LIST NULL +READ_ONLY NO +COMMAND_LINE_ARGUMENT REQUIRED VARIABLE_NAME INNODB_READ_AHEAD_THRESHOLD SESSION_VALUE NULL GLOBAL_VALUE 56 diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc index ecf85a81638..1f278b04e35 100644 --- a/storage/innobase/handler/ha_innodb.cc +++ b/storage/innobase/handler/ha_innodb.cc @@ -15971,6 +15971,10 @@ ha_innobase::external_lock( if (trx->n_mysql_tables_in_use == 0) { + /* Set the n_acquire_tickets_to_enter to zero because it has + ended the statement at this moment */ + trx->n_acquire_tickets_to_enter = 0; + trx->mysql_n_tables_locked = 0; m_prebuilt->used_in_HANDLER = FALSE; @@ -20377,6 +20381,16 @@ static MYSQL_SYSVAR_ULONG(concurrency_tickets, srv_n_free_tickets_to_enter, "Number of times a thread is allowed to enter InnoDB within the same SQL query after it has once got the ticket", NULL, NULL, 5000L, 1L, ~0UL, 0); +static MYSQL_SYSVAR_BOOL(rds_adaptive_tickets_algo, srv_adaptive_tickets_algo, + PLUGIN_VAR_RQCMDARG, + "Whether to enable the adaptive tickets algorithm", + NULL, NULL, FALSE); + +static MYSQL_SYSVAR_ULONG(rds_min_concurrency_tickets, srv_min_n_free_tickets_to_enter, + PLUGIN_VAR_RQCMDARG, + "The lower bound of the concurrency_tickets when rds_adaptive_tickets_algo is enabled", + NULL, NULL, 50L, 1L, ~0UL, 0); + static MYSQL_SYSVAR_BOOL(deadlock_detect, innobase_deadlock_detect, PLUGIN_VAR_NOCMDARG, "Enable/disable InnoDB deadlock detector (default ON)." @@ -21067,6 +21081,8 @@ static struct st_mysql_sys_var* innobase_system_variables[]= { MYSQL_SYSVAR(checksums), MYSQL_SYSVAR(commit_concurrency), MYSQL_SYSVAR(concurrency_tickets), + MYSQL_SYSVAR(rds_adaptive_tickets_algo), + MYSQL_SYSVAR(rds_min_concurrency_tickets), MYSQL_SYSVAR(compression_level), MYSQL_SYSVAR(data_file_path), MYSQL_SYSVAR(temp_data_file_path), diff --git a/storage/innobase/include/srv0srv.h b/storage/innobase/include/srv0srv.h index 20206f9d9eb..00cc4180b40 100644 --- a/storage/innobase/include/srv0srv.h +++ b/storage/innobase/include/srv0srv.h @@ -542,6 +542,10 @@ extern ulong srv_n_free_tickets_to_enter; extern ulong srv_thread_sleep_delay; extern uint srv_spin_wait_delay; +/* Whether to enable adaptive tickets algorithm */ +extern my_bool srv_adaptive_tickets_algo; +extern ulong srv_min_n_free_tickets_to_enter; + extern ulint srv_truncated_status_writes; /** Number of initialized rollback segments for persistent undo log */ extern ulong srv_available_undo_logs; diff --git a/storage/innobase/include/trx0trx.h b/storage/innobase/include/trx0trx.h index 6c9223f31be..4410728d14d 100644 --- a/storage/innobase/include/trx0trx.h +++ b/storage/innobase/include/trx0trx.h @@ -984,6 +984,14 @@ struct trx_t { field contains the end offset of the binlog entry */ /*------------------------------*/ + ulint n_acquire_tickets_to_enter; + /*!< number of times the current SQL + statement has entered innodb to acquire + tickets, increase each time, reset + to zero at the end of current SQL + statement. This is used for adaptive + tickets algorithm */ + /*------------------------------*/ ib_uint32_t n_mysql_tables_in_use; /*!< number of Innobase tables used in the processing of the current SQL statement in MySQL */ diff --git a/storage/innobase/srv/srv0conc.cc b/storage/innobase/srv/srv0conc.cc index 9e2aa7d7af4..be0cb28e3f8 100644 --- a/storage/innobase/srv/srv0conc.cc +++ b/storage/innobase/srv/srv0conc.cc @@ -49,6 +49,9 @@ Created 2011/04/18 Sunny Bains SQL query after it has once got the ticket. */ ulong srv_n_free_tickets_to_enter = 500; +my_bool srv_adaptive_tickets_algo; +ulong srv_min_n_free_tickets_to_enter; + /** Maximum sleep delay (in micro-seconds), value of 0 disables it. */ ulong srv_adaptive_max_sleep_delay = 150000; @@ -82,6 +85,35 @@ struct srv_conc_t { /* Control variables for tracking concurrency. */ static srv_conc_t srv_conc; +/*********************************************************************//** +Calculate how many tickets should assigned to current statement. +If adaptive algorithm(innodb_rds_adaptive_tickets_algo) is disabled, +return srv_n_free_tickets_to_enter as Oracle does; otherwise tickets number +is decreased exponentially according to the number of times current statement +entered innodb to acquire tickets. +*/ +static inline +ulint +srv_conc_calc_tickets( +/*================*/ + trx_t* trx) /*!< in: transaction that wants to + enter InnoDB */ +{ + ulint tickets = srv_n_free_tickets_to_enter; + if (!srv_adaptive_tickets_algo) { + return tickets; + } + + if (thd_trx_is_read_only(trx->mysql_thd) + && tickets > srv_min_n_free_tickets_to_enter) { + tickets >>= (trx->n_acquire_tickets_to_enter - 1); + } + + return ((tickets < srv_min_n_free_tickets_to_enter) + ? srv_min_n_free_tickets_to_enter + : tickets); +} + /*********************************************************************//** Note that a user thread is entering InnoDB. */ static @@ -92,7 +124,8 @@ srv_enter_innodb_with_tickets( to enter InnoDB */ { trx->declared_to_be_inside_innodb = TRUE; - trx->n_tickets_to_enter_innodb = srv_n_free_tickets_to_enter; + trx->n_acquire_tickets_to_enter++; + trx->n_tickets_to_enter_innodb = srv_conc_calc_tickets(trx); } /*********************************************************************//** diff --git a/storage/innobase/trx/trx0trx.cc b/storage/innobase/trx/trx0trx.cc index 91e60571438..30132be8f37 100644 --- a/storage/innobase/trx/trx0trx.cc +++ b/storage/innobase/trx/trx0trx.cc @@ -355,6 +355,8 @@ trx_create_low() DBUG_LOG("trx", "Create: " << trx); + trx->n_acquire_tickets_to_enter = 0; + heap = mem_heap_create(sizeof(ib_vector_t) + sizeof(void*) * 8); alloc = ib_heap_allocator_create(heap); -- 2.20.1