Update manticore config

DOCKER.md

@@ -74,6 +74,12 @@ enable Manticore auth by default, but if auth is enabled on the server set eithe
 HTTP diagnostics. Roll auth out in staging first; anonymous local Docker usage
 continues to work with these variables blank.
 
+Native Ubuntu/Debian package installs are managed by `systemd`, not Docker. If
+the package install fails while starting `manticore.service`, especially with
+`Status: "Replaying binlogs..."` and `accept() failed ... Too many open files`,
+use [`docs/manticore-ubuntu-package.md`](docs/manticore-ubuntu-package.md) to
+raise the service file descriptor limit and finish `dpkg` configuration.
+
 ## Make Targets
 
 Run `make` or `make help` to see all targets, grouped by section.

config/manticore.conf

@@ -93,6 +93,11 @@ searchd
 	# https://manual.manticoresearch.com/Server_settings/Searchd#max_packet_size
 	max_packet_size		= 16M
 
+	# maximum number of files searchd may keep open
+	# package/systemd installs must also set LimitNOFILE at least this high
+	# https://manual.manticoresearch.com/Server_settings/Searchd#max_open_files
+	max_open_files		= 65535
+
 	# max allowed per-query filter count
 	# optional, default is 256
 	# https://manual.manticoresearch.com/Server_settings/Searchd#max_filters