Don't force flush state files on nodeos exit

[matthewdarwin]

Don't force flush state files on nodeos exit. When state files are on a zfs disk with lots of I/O (this a large server with many applications on it), it can take a long time for all the data to flush to disk. In this example, it took 30+ minutes to stop nodeos

Nov  7 13:20:21 eos-sfdm41 nodeos[1080]: CHAINBASE: Writing "state" database file, 94% complete...
Nov  7 13:20:22 eos-sfdm41 nodeos[1080]: CHAINBASE: Writing "state" database file, 94% complete...
Nov  7 13:20:23 eos-sfdm41 nodeos[1080]: CHAINBASE: Writing "state" database file, 95% complete...
Nov  7 13:20:24 eos-sfdm41 nodeos[1080]: CHAINBASE: Writing "state" database file, 95% complete...
Nov  7 13:20:25 eos-sfdm41 nodeos[1080]: CHAINBASE: Writing "state" database file, 96% complete...
Nov  7 13:20:26 eos-sfdm41 nodeos[1080]: CHAINBASE: Writing "state" database file, 97% complete...
Nov  7 13:20:27 eos-sfdm41 nodeos[1080]: CHAINBASE: Writing "state" database file, 98% complete...
Nov  7 13:20:28 eos-sfdm41 nodeos[1080]: CHAINBASE: Writing "state" database file, 98% complete...
Nov  7 13:20:29 eos-sfdm41 nodeos[1080]: CHAINBASE: Writing "state" database file, 99% complete...
Nov  7 13:20:29 eos-sfdm41 nodeos[1080]: CHAINBASE: Writing "state" database file, flushing buffers...
Nov  7 13:42:29 eos-sfdm41 nodeos[1080]: CHAINBASE: Writing "state" database file, complete.
Nov  7 13:52:33 eos-sfdm41 nodeos[1080]: info  2023-11-07T13:52:33.557 nodeos    http_plugin.cpp:479           plugin_shutdown      ] exit shutdown
Nov  7 13:52:33 eos-sfdm41 nodeos[1080]: info  2023-11-07T13:52:33.750 nodeos    main.cpp:185                  main                 ] nodeos successfully exiting

This is nodeos 3.2.4

[bhazzard]

Flushing on exit is important to maintain consistency. The new mapped private mode in 5.0 may shutdown more quickly. I wonder if that would address your pain point?

[bhazzard]

Closing: When we have a chance to invest in this area, we're more likely to spend it improving the performance of writing out state.