diff options
Diffstat (limited to 'innobase/trx/trx0purge.c')
| -rw-r--r-- | innobase/trx/trx0purge.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/innobase/trx/trx0purge.c b/innobase/trx/trx0purge.c index 3d5f0d3f03a..6726d7ca609 100644 --- a/innobase/trx/trx0purge.c +++ b/innobase/trx/trx0purge.c @@ -295,6 +295,9 @@ trx_purge_add_update_undo_to_history( /* Add the log as the first in the history list */ flst_add_first(rseg_header + TRX_RSEG_HISTORY, undo_header + TRX_UNDO_HISTORY_NODE, mtr); + mutex_enter(&kernel_mutex); + trx_sys->rseg_history_len++; + mutex_exit(&kernel_mutex); /* Write the trx number to the undo log header */ mlog_write_dulint(undo_header + TRX_UNDO_TRX_NO, trx->no, mtr); @@ -386,6 +389,12 @@ loop: flst_cut_end(rseg_hdr + TRX_RSEG_HISTORY, log_hdr + TRX_UNDO_HISTORY_NODE, n_removed_logs, &mtr); + + mutex_enter(&kernel_mutex); + ut_ad(trx_sys->rseg_history_len >= n_removed_logs); + trx_sys->rseg_history_len -= n_removed_logs; + mutex_exit(&kernel_mutex); + freed = FALSE; while (!freed) { @@ -470,6 +479,11 @@ loop: } if (cmp >= 0) { + mutex_enter(&kernel_mutex); + ut_a(trx_sys->rseg_history_len >= n_removed_logs); + trx_sys->rseg_history_len -= n_removed_logs; + mutex_exit(&kernel_mutex); + flst_truncate_end(rseg_hdr + TRX_RSEG_HISTORY, log_hdr + TRX_UNDO_HISTORY_NODE, n_removed_logs, &mtr); @@ -1031,6 +1045,54 @@ trx_purge(void) purge_sys->view = NULL; mem_heap_empty(purge_sys->heap); + /* Determine how much data manipulation language (DML) statements + need to be delayed in order to reduce the lagging of the purge + thread. */ + srv_dml_needed_delay = 0; /* in microseconds; default: no delay */ + + /* If we cannot advance the 'purge view' because of an old + 'consistent read view', then the DML statements cannot be delayed. + Also, srv_max_purge_lag <= 0 means 'infinity'. */ + if (srv_max_purge_lag > 0 + && !UT_LIST_GET_LAST(trx_sys->view_list)) { + float ratio = (float) trx_sys->rseg_history_len + / srv_max_purge_lag; + if (ratio > ULINT_MAX / 10000) { + /* Avoid overflow: maximum delay is 4295 seconds */ + srv_dml_needed_delay = ULINT_MAX; + } else if (ratio > 1) { + /* If the history list length exceeds the + innodb_max_purge_lag, the + data manipulation statements are delayed + by at least 5000 microseconds. */ + srv_dml_needed_delay = (ulint) ((ratio - .5) * 10000); + } + } + + /* Determine how much data manipulation language (DML) statements + need to be delayed in order to reduce the lagging of the purge + thread. */ + srv_dml_needed_delay = 0; /* in microseconds; default: no delay */ + + /* If we cannot advance the 'purge view' because of an old + 'consistent read view', then the DML statements cannot be delayed. + Also, srv_max_purge_lag <= 0 means 'infinity'. */ + if (srv_max_purge_lag > 0 + && !UT_LIST_GET_LAST(trx_sys->view_list)) { + float ratio = (float) trx_sys->rseg_history_len + / srv_max_purge_lag; + if (ratio > ULINT_MAX / 10000) { + /* Avoid overflow: maximum delay is 4295 seconds */ + srv_dml_needed_delay = ULINT_MAX; + } else if (ratio > 1) { + /* If the history list length exceeds the + innodb_max_purge_lag, the + data manipulation statements are delayed + by at least 5000 microseconds. */ + srv_dml_needed_delay = (ulint) ((ratio - .5) * 10000); + } + } + purge_sys->view = read_view_oldest_copy_or_open_new(NULL, purge_sys->heap); mutex_exit(&kernel_mutex); |