division by zero

[wywerne]

On RHEL 7 with MariaDB 10.8.3 fresh installation with last mysqltuner.pl, i have this error :

Illegal division by zero at /usr/local/bin/mysqltuner line 6137 (#1)
(F) You tried to divide a number by 0. Either something was wrong in
your logic, or you need to put a conditional in to guard against
meaningless input.

Uncaught exception from user code:
Illegal division by zero at /usr/local/bin/mysqltuner line 6137.
main::mysql_innodb() called at /usr/local/bin/mysqltuner line 6881

Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 926
Server version: 10.8.3-MariaDB-log MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> show variables like 'Innodb_%';
+------------------------------------------+------------------------+
| Variable_name | Value |
+------------------------------------------+------------------------+
| innodb_adaptive_flushing | ON |
| innodb_adaptive_flushing_lwm | 10.000000 |
| innodb_adaptive_hash_index | OFF |
| innodb_adaptive_hash_index_parts | 8 |
| innodb_autoextend_increment | 64 |
| innodb_autoinc_lock_mode | 1 |
| innodb_buf_dump_status_frequency | 0 |
| innodb_buffer_pool_chunk_size | 393347072 |
| innodb_buffer_pool_dump_at_shutdown | ON |
| innodb_buffer_pool_dump_now | OFF |
| innodb_buffer_pool_dump_pct | 25 |
| innodb_buffer_pool_filename | ib_buffer_pool |
| innodb_buffer_pool_load_abort | OFF |
| innodb_buffer_pool_load_at_startup | ON |
| innodb_buffer_pool_load_now | OFF |
| innodb_buffer_pool_size | 25174212608 |
| innodb_change_buffer_max_size | 25 |
| innodb_change_buffering | none |
| innodb_checksum_algorithm | full_crc32 |
| innodb_cmp_per_index_enabled | OFF |
| innodb_compression_algorithm | zlib |
| innodb_compression_default | OFF |
| innodb_compression_failure_threshold_pct | 5 |
| innodb_compression_level | 6 |
| innodb_compression_pad_pct_max | 50 |
| innodb_data_file_path | ibdata1:12M:autoextend |
| innodb_data_home_dir | |
| innodb_deadlock_detect | ON |
| innodb_deadlock_report | full |
| innodb_default_encryption_key_id | 1 |
| innodb_default_row_format | dynamic |
| innodb_defragment | OFF |
| innodb_defragment_fill_factor | 0.900000 |
| innodb_defragment_fill_factor_n_recs | 20 |
| innodb_defragment_frequency | 40 |
| innodb_defragment_n_pages | 7 |
| innodb_defragment_stats_accuracy | 0 |
| innodb_disable_sort_file_cache | OFF |
| innodb_doublewrite | ON |
| innodb_encrypt_log | OFF |
| innodb_encrypt_tables | OFF |
| innodb_encrypt_temporary_tables | OFF |
| innodb_encryption_rotate_key_age | 1 |
| innodb_encryption_rotation_iops | 100 |
| innodb_encryption_threads | 0 |
| innodb_fast_shutdown | 1 |
| innodb_fatal_semaphore_wait_threshold | 600 |
| innodb_file_per_table | ON |
| innodb_fill_factor | 100 |
| innodb_flush_log_at_timeout | 1 |
| innodb_flush_log_at_trx_commit | 1 |
| innodb_flush_method | O_DIRECT |
| innodb_flush_neighbors | 1 |
| innodb_flush_sync | ON |
| innodb_flushing_avg_loops | 30 |
| innodb_force_primary_key | OFF |
| innodb_force_recovery | 0 |
| innodb_ft_aux_table | |
| innodb_ft_cache_size | 8000000 |
| innodb_ft_enable_diag_print | OFF |
| innodb_ft_enable_stopword | ON |
| innodb_ft_max_token_size | 84 |
| innodb_ft_min_token_size | 3 |
| innodb_ft_num_word_optimize | 2000 |
| innodb_ft_result_cache_limit | 2000000000 |
| innodb_ft_server_stopword_table | |
| innodb_ft_sort_pll_degree | 2 |
| innodb_ft_total_cache_size | 640000000 |
| innodb_ft_user_stopword_table | |
| innodb_immediate_scrub_data_uncompressed | OFF |
| innodb_instant_alter_column_allowed | add_drop_reorder |
| innodb_io_capacity | 200 |
| innodb_io_capacity_max | 2000 |
| innodb_lock_wait_timeout | 50 |
| innodb_log_buffer_size | 8388608 |
| innodb_log_file_size | 536870912 |
| innodb_log_group_home_dir | ./ |
| innodb_lru_flush_size | 32 |
| innodb_lru_scan_depth | 1536 |
| innodb_max_dirty_pages_pct | 90.000000 |
| innodb_max_dirty_pages_pct_lwm | 0.000000 |
| innodb_max_purge_lag | 0 |
| innodb_max_purge_lag_delay | 0 |
| innodb_max_purge_lag_wait | 4294967295 |
| innodb_max_undo_log_size | 10485760 |
| innodb_monitor_disable | |
| innodb_monitor_enable | all |
| innodb_monitor_reset | |
| innodb_monitor_reset_all | |
| innodb_old_blocks_pct | 37 |
| innodb_old_blocks_time | 1000 |
| innodb_online_alter_log_max_size | 134217728 |
| innodb_open_files | 8192 |
| innodb_optimize_fulltext_only | OFF |
| innodb_page_size | 16384 |
| innodb_prefix_index_cluster_optimization | OFF |
| innodb_print_all_deadlocks | OFF |
| innodb_purge_batch_size | 300 |
| innodb_purge_rseg_truncate_frequency | 128 |
| innodb_purge_threads | 4 |
| innodb_random_read_ahead | OFF |
| innodb_read_ahead_threshold | 56 |
| innodb_read_io_threads | 4 |
| innodb_read_only | OFF |
| innodb_read_only_compressed | OFF |
| innodb_rollback_on_timeout | OFF |
| innodb_sort_buffer_size | 1048576 |
| innodb_spin_wait_delay | 4 |
| innodb_stats_auto_recalc | ON |
| innodb_stats_include_delete_marked | OFF |
| innodb_stats_method | nulls_equal |
| innodb_stats_modified_counter | 0 |
| innodb_stats_on_metadata | OFF |
| innodb_stats_persistent | ON |
| innodb_stats_persistent_sample_pages | 20 |
| innodb_stats_traditional | ON |
| innodb_stats_transient_sample_pages | 8 |
| innodb_status_output | OFF |
| innodb_status_output_locks | OFF |
| innodb_strict_mode | ON |
| innodb_sync_spin_loops | 30 |
| innodb_table_locks | ON |
| innodb_temp_data_file_path | ibtmp1:12M:autoextend |
| innodb_tmpdir | |
| innodb_undo_directory | ./ |
| innodb_undo_log_truncate | OFF |
| innodb_undo_tablespaces | 0 |
| innodb_use_atomic_writes | ON |
| innodb_use_native_aio | ON |
| innodb_version | 10.8.3 |
| innodb_write_io_threads | 4 |
+------------------------------------------+------------------------+
131 rows in set (0.003 sec)

regard,

[sdn-dev]

Facing a similar issue on Ubuntu 22.04 with MariaDB 10.9.2:

Illegal division by zero at ./mysqltuner.pl line 6138 (#1)
(F) You tried to divide a number by 0. Either something was wrong in
your logic, or you need to put a conditional in to guard against
meaningless input.

Uncaught exception from user code:
Illegal division by zero at ./mysqltuner.pl line 6138.
main::mysql_innodb() called at ./mysqltuner.pl line 6881

[brunom63]

Same here but with innodb_log_files_in_group on Docker container version:

mariadb  Ver 15.1 Distrib 10.9.3-MariaDB, for debian-linux-gnu (aarch64) using  EditLine wrapper

[brunom63]

Oops, sorry, my bad. This issue was fixed on version 1.8.

[bperel]

In my case, the error still occurs in version 2.0.9

[muuvmuuv]

Seeing this as well, on 16GB with Xeon E5-2640:

[OK] Innodb_buffer_pool_size aligned with Innodb_buffer_pool_chunk_size & Innodb_buffer_pool_instances
[!!] InnoDB Read buffer efficiency: -516.98% (-8737 hits / 1690 total)
[!!] InnoDB Write Log efficiency: 0% (0 hits / 0 total)
Illegal division by zero at mysqltuner.pl line 6157 (#1)
    (F) You tried to divide a number by 0.  Either something was wrong in
    your logic, or you need to put a conditional in to guard against
    meaningless input.

Uncaught exception from user code:
	Illegal division by zero at mysqltuner.pl line 6157.
	main::mysql_innodb() called at mysqltuner.pl line 6900

[mysqld]
character_set_server = utf8mb4
collation_server = utf8mb4_unicode_520_ci
port = 3306
bind-address = 0.0.0.0
skip_name_resolve = On
datadir = /var/lib/mysql
tmpdir = /tmp
log_error = /var/log/mysql/mysqld.log
socket = /run/mysqld/mysqld.sock
max_connections = 200 # as required per situation
# wait_timeout = 1800
max_connect_errors = 1000
connect_timeout = 20
performance_schema = On
innodb_stats_on_metadata = On
table_open_cache = 8192
table_definition_cache = 4496
join_buffer_size = 256
max_allowed_packet = 512M
key_buffer_size = 4M
innodb_buffer_pool_size = 2G
innodb_data_file_path = ibdata1:10M:autoextend
innodb_fast_shutdown = 0
innodb_file_per_table
innodb_flush_method = O_DIRECT
innodb_flush_log_at_trx_commit = 1 # needed for ACID
innodb_lock_wait_timeout = 120 # default 50 sec
innodb_log_buffer_size = 32M
innodb_log_files_in_group = 2
innodb_log_file_size = 512M
innodb_max_dirty_pages_pct = 75
default_storage-engine = InnoDB

[mysqldump]
single_transaction = 1
extended_insert = 1
quick
max_allowed_packet = 512M

[client]
socket = /run/mysqld/mysqld.sock

[mikevoets]

As a temporary workaround, I went to line 6157 in the file and added in a condition to check that the denominator is higher than zero ($mystat{'Innodb_log_writes'} > 0.000001), like this:

if (    defined( $mystat{'Innodb_log_waits'} )
        and defined( $mystat{'Innodb_log_writes'} )
        and $mystat{'Innodb_log_writes'} > 0.000001 )
{
 ...

[jmrenouard]

MySQLtuner.pl 2.1.1+ Line 6192:

` # InnoDB Log Waits
$mystat{'Innodb_log_waits_computed'} = 0;

if (    defined( $mystat{'Innodb_log_waits'} )
    and defined( $mystat{'Innodb_log_writes'} ) and $mystat{'Innodb_log_writes'} > 0.000001 )
{
    $mystat{'Innodb_log_waits_computed'} =
      $mystat{'Innodb_log_waits'} / $mystat{'Innodb_log_writes'};
}
else {
    undef $mystat{'Innodb_log_waits_computed'};
}

`

This issue seems to be fixed :)