docs/modules/servers/partials/configure/jvm.adoc - james-project - Git at Google

 This file may contain any additional system properties for tweaking JVM execution. When you normally would add a command line option `-Dmy.property=whatever`, you can put it in this file as `my.property=whatever` instead. These properties will be added as system properties on server start.

 Note that in some rare cases this might not work,
 when a property affects very early JVM start behaviour.

 For testing purposes, you may specify a different file path via the command line option `-Dextra.props=/some/other/jvm.properties`.

 == Control the threshold memory
 This governs the threshold MimeMessageInputStreamSource relies on for storing MimeMessage content on disk.

 In `jvm.properties`
 ----
 james.message.memory.threshold=12K
 ----

 (Optional). String (size, integer + size units, example: `12 KIB`, supported units are bytes KIB MIB GIB TIB). Defaults to 100KIB.

 == Enable the copy of message in memory
 Should MimeMessageWrapper use a copy of the message in memory? Or should bigger message exceeding james.message.memory.threshold
 be copied to temporary files?

 ----
 james.message.usememorycopy=true
 ----

 Optional. Boolean. Defaults to false. Recommended value is false.

 == Running resource leak detection
 It is used to detect a resource not be disposed of before it's garbage-collected.

 In `jvm.properties`
 ----
 james.lifecycle.leak.detection.mode=advanced
 ----

 Allowed mode values are: none, simple, advanced, testing

 The purpose of each mode is introduced in `config-system.xml`

 == Disabling host information in protocol MDC logging context

 Should we add the host in the MDC logging context for incoming IMAP, SMTP, POP3? Doing so, a DNS resolution
 is attempted for each incoming connection, which can be costly. Remote IP is always added to the logging context.


 In `jvm.properties`
 ----
 james.protocols.mdc.hostname=false
 ----

 Optional. Boolean. Defaults to true.

 == Change the encoding type used for the blobId

 By default, the blobId is encoded in base64 url. The property `james.blob.id.hash.encoding` allows to change the encoding type.
 The support value are: base16, hex, base32, base32Hex, base64, base64Url.

 Ex in `jvm.properties`
 ----
 james.blob.id.hash.encoding=base16
 ----

 Optional. String. Defaults to base64Url.

 == Improve listing support for MinIO

 Due to blobs being stored in folder, adding `/` in blobs name emulates folder and avoids blobs to be all stored in a
 same folder, thus improving listing.

 Instead of `1_628_36825033-d835-4490-9f5a-eef120b1e85c` the following blob id will be used: `1/628/3/6/8/2/5033-d835-4490-9f5a-eef120b1e85c`

 To enable blob hierarchy compatible with MinIO add in `jvm.properties`:

 ----
 james.s3.minio.compatibility.mode=true
 ----

 == JMAP Quota draft compatibility

 Some JMAP clients depend on the JMAP Quota draft specifications. The property `james.jmap.quota.draft.compatibility` allows
 to enable JMAP Quota draft compatibility for those clients and allow them a time window to adapt to the RFC-9245 JMAP Quota.

 Optional. Boolean. Default to false.

 Ex in `jvm.properties`
 ----
 james.jmap.quota.draft.compatibility=true
 ----
 To enable the compatibility.

 == Enable Reactor Netty metrics for JMAP server

 Allow to enable https://projectreactor.io/docs/netty/1.1.19/reference/index.html#_metrics_4[Reactor Netty metrics] for JMAP server which would provide useful debug information.

 Optional. Boolean. Default to false.

 Ex in `jvm.properties`:
 ----
 james.jmap.reactor.netty.metrics.enabled=true
 ----
 To enable the metrics.

 == Enable S3 metrics

 James supports extracting some S3 client-level metrics e.g. number of connections being used, time to acquire an S3 connection, total time to finish a S3 request...

 The property `james.s3.metrics.enabled` allows to enable S3 metrics collection. Please pay attention that enable this
 would impact a bit on S3 performance.

 Optional. Boolean. Default to true.

 Ex in `jvm.properties`
 ----
 james.s3.metrics.enabled=false
 ----
 To disable the S3 metrics.

 == Reactor Stream Prefetch

 Prefetch to use in Reactor to stream convertions (S3 => InputStream). Default to 1.
 Higher values will tend to block less often at the price of higher memory consumptions.

 Ex in `jvm.properties`
 ----
 # james.reactor.inputstream.prefetch=4
 ----


 == Disable mailet container check at James startup

 James is doing checks on startup for validating mailet container configuration against a set of
 business rules, for instance making sure that the `bcc` header is being removed via
 `RemoveMimeHeader` mailet in the mail processing pipeline defined in `mailetcontainer.xml` file.

 It could be useful for some administrators that know what they are doing to disable such checks
 during James startup.

 Optional. Boolean. Defaults to true.

 Ex in `jvm.properties`
 ----
 james.mailet.container.check.enabled=false
 ----
 To disable the mailet container check at James startup.

 == Relax mailbox name validation

 The property `james.relaxed.mailbox.name.validation` allows to accept `*` and `%` characters in mailbox name.

 Optional. Boolean. Default to false.

 Ex in `jvm.properties`
 ----
 james.relaxed.mailbox.name.validation=true
 ----
 To relax validating `\*` and `%` characters in the mailbox name. Be careful as `%` and `*` are ambiguous for the LIST / LSUB commands that interpret those as wildcard thus returning all mailboxes matching the pattern.
	This file may contain any additional system properties for tweaking JVM execution. When you normally would add a command line option `-Dmy.property=whatever`, you can put it in this file as `my.property=whatever` instead. These properties will be added as system properties on server start.

	Note that in some rare cases this might not work,
	when a property affects very early JVM start behaviour.

	For testing purposes, you may specify a different file path via the command line option `-Dextra.props=/some/other/jvm.properties`.

	== Control the threshold memory
	This governs the threshold MimeMessageInputStreamSource relies on for storing MimeMessage content on disk.

	In `jvm.properties`
	----
	james.message.memory.threshold=12K
	----

	(Optional). String (size, integer + size units, example: `12 KIB`, supported units are bytes KIB MIB GIB TIB). Defaults to 100KIB.

	== Enable the copy of message in memory
	Should MimeMessageWrapper use a copy of the message in memory? Or should bigger message exceeding james.message.memory.threshold
	be copied to temporary files?

	----
	james.message.usememorycopy=true
	----

	Optional. Boolean. Defaults to false. Recommended value is false.

	== Running resource leak detection
	It is used to detect a resource not be disposed of before it's garbage-collected.

	In `jvm.properties`
	----
	james.lifecycle.leak.detection.mode=advanced
	----

	Allowed mode values are: none, simple, advanced, testing

	The purpose of each mode is introduced in `config-system.xml`

	== Disabling host information in protocol MDC logging context

	Should we add the host in the MDC logging context for incoming IMAP, SMTP, POP3? Doing so, a DNS resolution
	is attempted for each incoming connection, which can be costly. Remote IP is always added to the logging context.


	In `jvm.properties`
	----
	james.protocols.mdc.hostname=false
	----

	Optional. Boolean. Defaults to true.

	== Change the encoding type used for the blobId

	By default, the blobId is encoded in base64 url. The property `james.blob.id.hash.encoding` allows to change the encoding type.
	The support value are: base16, hex, base32, base32Hex, base64, base64Url.

	Ex in `jvm.properties`
	----
	james.blob.id.hash.encoding=base16
	----

	Optional. String. Defaults to base64Url.

	== Improve listing support for MinIO

	Due to blobs being stored in folder, adding `/` in blobs name emulates folder and avoids blobs to be all stored in a
	same folder, thus improving listing.

	Instead of `1_628_36825033-d835-4490-9f5a-eef120b1e85c` the following blob id will be used: `1/628/3/6/8/2/5033-d835-4490-9f5a-eef120b1e85c`

	To enable blob hierarchy compatible with MinIO add in `jvm.properties`:

	----
	james.s3.minio.compatibility.mode=true
	----

	== JMAP Quota draft compatibility

	Some JMAP clients depend on the JMAP Quota draft specifications. The property `james.jmap.quota.draft.compatibility` allows
	to enable JMAP Quota draft compatibility for those clients and allow them a time window to adapt to the RFC-9245 JMAP Quota.

	Optional. Boolean. Default to false.

	Ex in `jvm.properties`
	----
	james.jmap.quota.draft.compatibility=true
	----
	To enable the compatibility.

	== Enable Reactor Netty metrics for JMAP server

	Allow to enable https://projectreactor.io/docs/netty/1.1.19/reference/index.html#_metrics_4[Reactor Netty metrics] for JMAP server which would provide useful debug information.

	Optional. Boolean. Default to false.

	Ex in `jvm.properties`:
	----
	james.jmap.reactor.netty.metrics.enabled=true
	----
	To enable the metrics.

	== Enable S3 metrics

	James supports extracting some S3 client-level metrics e.g. number of connections being used, time to acquire an S3 connection, total time to finish a S3 request...

	The property `james.s3.metrics.enabled` allows to enable S3 metrics collection. Please pay attention that enable this
	would impact a bit on S3 performance.

	Optional. Boolean. Default to true.

	Ex in `jvm.properties`
	----
	james.s3.metrics.enabled=false
	----
	To disable the S3 metrics.

	== Reactor Stream Prefetch

	Prefetch to use in Reactor to stream convertions (S3 => InputStream). Default to 1.
	Higher values will tend to block less often at the price of higher memory consumptions.

	Ex in `jvm.properties`
	----
	# james.reactor.inputstream.prefetch=4
	----


	== Disable mailet container check at James startup

	James is doing checks on startup for validating mailet container configuration against a set of
	business rules, for instance making sure that the `bcc` header is being removed via
	`RemoveMimeHeader` mailet in the mail processing pipeline defined in `mailetcontainer.xml` file.

	It could be useful for some administrators that know what they are doing to disable such checks
	during James startup.

	Optional. Boolean. Defaults to true.

	Ex in `jvm.properties`
	----
	james.mailet.container.check.enabled=false
	----
	To disable the mailet container check at James startup.

	== Relax mailbox name validation

	The property `james.relaxed.mailbox.name.validation` allows to accept `*` and `%` characters in mailbox name.

	Optional. Boolean. Default to false.

	Ex in `jvm.properties`
	----
	james.relaxed.mailbox.name.validation=true
	----
	To relax validating `\` and `%` characters in the mailbox name. Be careful as `%` and `` are ambiguous for the LIST / LSUB commands that interpret those as wildcard thus returning all mailboxes matching the pattern.