Crash in Item_param::convert_str_value

210813  9:03:30 [ERROR] mysqld got signal 11 ;

This could be because you hit a bug. It is also possible that this binary

or one of the libraries it was linked against is corrupt, improperly built,

or misconfigured. This error can also be caused by malfunctioning hardware.

To report this bug, see https://mariadb.com/kb/en/reporting-bugs

We will try our best to scrape up some info that will hopefully help

diagnose the problem, but since we have already crashed, 

something is definitely wrong and this may fail.

Server version: 10.5.12-MariaDB-1:10.5.12+maria~focal-log

key_buffer_size=134217728

read_buffer_size=131072

max_used_connections=11

max_threads=153

thread_count=14

It is possible that mysqld could use up to 

key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 467871 K  bytes of memory

Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x7f29e8000c58

Attempting backtrace. You can use the following information to find out

where mysqld died. If you see no messages after this, something went

terribly wrong...

stack_bottom = 0x7f2a41491d58 thread_stack 0x49000

mysqld(my_print_stacktrace+0x32)[0x55b96c8b73a2]

Printing to addr2line failed

mysqld(handle_fatal_signal+0x485)[0x55b96c30a0b5]

/lib/x86_64-linux-gnu/libpthread.so.0(+0x153c0)[0x7f2a595623c0]

mysqld(my_string_metadata_get+0x1e)[0x55b96c90721e]

mysqld(_ZN10Item_param17convert_str_valueEP3THD+0xdf)[0x55b96c32f26f]

mysqld(+0x779347)[0x55b96c10b347]

mysqld(_ZN18Prepared_statement14set_parametersEP6StringPhS2_+0x6f)[0x55b96c10f96f]

mysqld(_ZN18Prepared_statement12execute_loopEP6StringbPhS2_+0x3a)[0x55b96c110a7a]

mysqld(+0x77f735)[0x55b96c111735]

mysqld(_Z19mysqld_stmt_executeP3THDPcj+0x30)[0x55b96c111950]

mysqld(_Z16dispatch_command19enum_server_commandP3THDPcjbb+0x1acf)[0x55b96c0f847f]

mysqld(_Z10do_commandP3THD+0x11c)[0x55b96c0fa30c]

mysqld(_Z24do_handle_one_connectionP7CONNECTb+0x421)[0x55b96c200a61]

mysqld(handle_one_connection+0x5d)[0x55b96c200edd]

mysqld(+0xbd0a36)[0x55b96c562a36]

/lib/x86_64-linux-gnu/libpthread.so.0(+0x9609)[0x7f2a59556609]

/lib/x86_64-linux-gnu/libc.so.6(clone+0x43)[0x7f2a59144293]

Trying to get some variables.

Some pointers may be invalid and cause the dump to abort.

Query (0x0): (null)

Connection ID (thread ID): 11

Status: NOT_KILLED

Optimizer switch: index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off

The manual page at https://mariadb.com/kb/en/how-to-produce-a-full-stack-trace-for-mysqld/ contains

information that should help you find out what is causing the crash.

We think the query pointer is invalid, but we will try to print it anyway. 

Query: 

Writing a core file...

Working directory at /var/lib/mysql

Resource Limits:

Limit                     Soft Limit           Hard Limit           Units     

Max cpu time              unlimited            unlimited            seconds   

Max file size             unlimited            unlimited            bytes     

Max data size             unlimited            unlimited            bytes     

Max stack size            8388608              unlimited            bytes     

Max core file size        unlimited            unlimited            bytes     

Max resident set          unlimited            unlimited            bytes     

Max processes             unlimited            unlimited            processes 

Max open files            1024                 1024                 files     

Max locked memory         65536                65536                bytes     

Max address space         unlimited            unlimited            bytes     

Max file locks            unlimited            unlimited            locks     

Max pending signals       127158               127158               signals   

Max msgqueue size         819200               819200               bytes     

Max nice priority         0                    0                    

Max realtime priority     0                    0                    

Max realtime timeout      unlimited            unlimited            us        

Core pattern: |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h

sysbench --time=0 --threads=5 --mysql-host=127.0.0.1 --mysql-port=4006 --mysql-user=maxuser --mysql-password=maxpwd --mysql-db=test --db-ps-mode=auto --skip_trx=on ./oltp_read_only.lua run

[maxscale]

threads=auto

[server1]

type=server

address=127.0.0.1

port=3000

protocol=MariaDBBackend

persistpoolmax=20

persistmaxtime=300s

[server2]

type=server

address=127.0.0.1

port=3001

protocol=MariaDBBackend

persistpoolmax=20

persistmaxtime=300s

[server3]

type=server

address=127.0.0.1

port=3002

protocol=MariaDBBackend

persistpoolmax=20

persistmaxtime=300s

[server4]

type=server

address=127.0.0.1

port=3003

protocol=MariaDBBackend

persistpoolmax=20

persistmaxtime=300s

[MariaDB-Monitor]

type=monitor

module=mariadbmon

servers=server1,server2,server3,server4

user=maxuser

password=maxpwd

monitor_interval=5000

[RW-Split-Router]

type=service

router=readwritesplit

servers=server1,server2,server3,server4

user=maxuser

password=maxpwd

idle_session_pool_time=0s

[RW-Split-Listener]

type=listener

service=RW-Split-Router

protocol=MariaDBClient

port=4006

diff --git a/server/core/routingworker.cc b/server/core/routingworker.cc

index 0d08600e4..23a6e78b3 100644

--- a/server/core/routingworker.cc

+++ b/server/core/routingworker.cc

@@ -465,7 +465,7 @@ void RoutingWorker::process_timeouts()

                 auto idle = MXS_CLOCK_TO_SEC(now - pClient->last_read());

                 pSes->tick(idle);

-                if (pooling_time >= 0 && idle > pooling_time && pSes->can_pool_backends())

+                if (pooling_time >= 0 && idle >= pooling_time && pSes->can_pool_backends())

                 {

                     for (auto& backend : pSes->backend_connections())

                     {