[id='jgroups-system-properties_{context}']
= Cluster transport properties

Use the following properties to customize JGroups cluster transport.

[%header,cols="1,3,2,1"]
|===

| System Property
| Description
| Default Value
| Required/Optional

| `jgroups.bind.address`
| Bind address for cluster transport.
| `SITE_LOCAL`
| Optional

| `jgroups.bind.port`
| Bind port for the socket.
| `7800`
| Optional

| `jgroups.mcast_addr`
| IP address for multicast, both discovery and inter-cluster communication. The IP address must be a valid "class D" address that is suitable for IP multicast.
| `239.6.7.8`
| Optional

| `jgroups.mcast_port`
| Port for the multicast socket.
| `46655`
| Optional

| `jgroups.ip_ttl`
| Time-to-live (TTL) for IP multicast packets. The value defines the number of network hops a packet can make before it is dropped.
| 2
| Optional

| `jgroups.thread_pool.min_threads`
| Minimum number of threads for the thread pool.
| 0
| Optional

| `jgroups.thread_pool.max_threads`
| Maximum number of threads for the thread pool.
| 200
| Optional

| `jgroups.join_timeout`
| Maximum number of milliseconds to wait for join requests to succeed.
| 2000
| Optional

|`jgroups.thread_dumps_threshold`
| Number of times a thread pool needs to be full before a thread dump is logged.
| 10000
| Optional

| `jgroups.fd.port-offset`
| Offset from `jgroups.bind.port` port for the FD (failure detection protocol) socket.
| `50000` (port `57800` )
| Optional

| `jgroups.frag_size`
| Maximum number of bytes in a message. Messages larger than that are fragmented.
| 60000
| Optional


| `jgroups.diag.enabled`
| Enables JGroups diagnostic probing.
| false
| Optional

|===

[role="_additional-resources"]
.Additional resources
* link:{jgroups_docs}#SystemProperties[JGroups system properties]
* link:{jgroups_docs}#protlist[JGroups protocol list]
