AW: BUG #15641: Autoprewarm worker fails to start on Windows with huge pages in use Old PostgreSQL community/pgsql-bugs x - Mailing list pgsql-bugs

Thank you for taking a look.

I encountered this problem after switching the production system and then found it also on the new created replica.

I have no knowledge of the shared memory areas involved.

I did some further investigation and tried to reproduce it on the old System (WS2016, PG 11.2) but there it worked fine (without and with huge pages activated!).

Even on a developer machine under WS2019, PG 11.2 the error did not occur (both cases running on different generation of intel machines, Haswell and Nehalem, under different Hypervisors, WS2012R2 and WS2019).

I am really confused to not being able to reproduce the error outside of production and replica instances...

The error caused a massive flood of the logs (about 800 MB in about 1 day, on SSD)

I'll try to investigate further by configuring a second replica tomorrow, using the configuration of the production system as done per pg_basebackup.

I looked at the non-default configuration settings but could not identify anything special.

Here is a current list of the production System having 4GB of memory allocated to the VM.
(all values with XXX are a little obfuscated).

Here, to avoid the error, pg_prewarm.autoprewarm is off!

             name              |              current_setting               |
-------------------------------+--------------------------------------------+
 application_name              | psql                                       |
 archive_command               | copy "xxxxxx"                              |
 archive_mode                  | on                                         |
 auto_explain.log_analyze      | off                                        |
 auto_explain.log_min_duration | -1                                         |
 client_encoding               | WIN1252                                    |
 cluster_name                  | XXX_PROD                                   |
 data_checksums                | on                                         |
 DateStyle                     | ISO, DMY                                   |
 default_text_search_config    | pg_catalog.german                          |
 dynamic_shared_memory_type    | windows                                    |
 effective_cache_size          | 8GB                                        |
 lc_collate                    | C                                          |
 lc_ctype                      | German_Germany.1252                        |
 lc_messages                   | C                                          |
 lc_monetary                   | German_Germany.1252                        |
 lc_numeric                    | German_Germany.1252                        |
 lc_time                       | German_Germany.1252                        |
 listen_addresses              | *                                          |
 log_destination               | stderr                                     |
 log_directory                 | <XXX_PATH_TO_LOG)                          |
 log_file_mode                 | 0640                                       |
 log_line_prefix               | XXX PRD %t %i %e %2l:>                     |
 log_statement                 | mod                                        |
 log_temp_files                | 0                                          |
 log_timezone                  | CET                                        |
 logging_collector             | on                                         |
 maintenance_work_mem          | 128MB                                      |
 max_connections               | 200                                        |
 max_stack_depth               | 2MB                                        |
 max_wal_size                  | 1GB                                        |
 min_wal_size                  | 80MB                                       |
 pg_prewarm.autoprewarm        | off                                        |
 pg_stat_statements.max        | 8000                                       |
 pg_stat_statements.track      | all                                        |
 random_page_cost              | 1                                          |
 search_path                   | public, archiv, ablage, admin              |
 server_encoding               | UTF8                                       |
 server_version                | 11.2                                       |
 shared_buffers                | 768MB                                      |
 shared_preload_libraries      | auto_explain,pg_stat_statements,pg_prewarm |
 temp_buffers                  | 32MB                                       |
 TimeZone                      | CET                                        |
 transaction_deferrable        | off                                        |
 transaction_isolation         | read committed                             |
 transaction_read_only         | off                                        |
 update_process_title          | off                                        |
 wal_buffers                   | 16MB                                       |
 wal_compression               | on                                         |
 wal_segment_size              | 16MB                                       |
 work_mem                      | 64MB                                       |
(51 Zeilen)


Thanks

Hans Buschmann