wrapper.backend.socket.bind.timeout
Kompatibel :3.6.3
Editionen :Professional EditionStandard EditionCommunity Edition
Betriebssysteme :WindowsMac OSXLinuxIBM AIXFreeBSDHP-UXSolarisIBM z/Linux

The Wrapper uses a backend connection (socket or pipe) to communicate with its monitored JVM. This connection is established, usually almost instantly, at startup before the Wrapper launches a JVM.

For socket connections, an additional step involves binding to the loopback address and a specific port. Typically, the loopback address is available, and the Wrapper selects the first available port within the configured range. However, in some configurations, it has been observed that the IPv4 and/or IPv6 addresses can temporarily detach from their network interface. This can happen, for example, when the loopback interface is managed by systemd-networkd. When systemd-networkd applies configuration changes, it briefly tears down and reconfigures interfaces, usually resulting in a few milliseconds of downtime during which the loopback addresses are unavailable.

Starting with Wrapper version 3.6.3, the Wrapper includes a retry mechanism for situations where the address is unavailable during binding. The wrapper.backend.socket.bind.timeout property configures the maximum duration, in seconds, for this retry mechanism. If the timeout elapses, the Wrapper will cease its attempts and stop.

On Unix, the default value is 5 seconds.

On Windows, since no similar downtime issue have been observed, the default value is 0 seconds, which disables the retry mechanism. However, this value can be changed if necessary.

NOTE

If wrapper.backend.type is set to AUTO or SOCKET and the loopback address is unavailable for SOCKET_IPv4 or SOCKET_IPv6, the Wrapper will not block on that type. Instead, it will immediately attempt to create a connection with the next type in the fallback order: SOCKET_IPv6, then SOCKET_IPv4, then PIPE (if applicable).

If no type succeeds in the current cycle, the retry mechanism will initiate a new cycle, continuing until a suitable type is found or timing out. This allows the Wrapper for more responsiveness on startup.

It is also possible to set wrapper.backend.type to a specific type and disable this fallback mechanism.

This is what can be seen in the logs when binding to IPv4 and IPv6 loopback addresses fails and wrapper.backend.type is set to SOCKET. 

INFO   | 2025/08/01 18:34:40.976 | wrapperp | Could not assign a name to the socket. Waiting 5 seconds...
INFO   | 2025/08/01 18:34:41.082 | wrapperp | Backend server started with SOCKET_IPv4.

Verweis: Port
  • wrapper.backend.type (3.5.8)

    Konfiguriert diwrapper.event.e Datenübertragung zwischen dem Wrapper-Prozess und der Klasse, die innerhalb der JVM läuft.

  • wrapper.port (1.0.0)

    Konfiguriert den Port, den der Wrapper nutzen wird, um sich mit der JVM zu verbinden.

  • wrapper.port.max (3.2.0)

    Legt die obere Grenze des Bereichs fest, den der Wrapper benutzen wird, um sich mit der JVM zu verbinden.

  • wrapper.port.min (3.2.0)

    Legt die untere Grenze des Bereichs fest, den der Wrapper benutzen wird, um sich mit der JVM zu verbinden.

  • wrapper.jvm.port (3.2.0)

    Konfiguriert den Port, den die JVM nutzt, um sich mit dem Wrapper zurückzuverbinden.

  • wrapper.jvm.port.max (3.2.0)

    Spezifiziert die obere Grenze des Port-Bereichs, den die JVM nutzt, um sich mit dem Wrapper zurückzuverbinden.

  • wrapper.jvm.port.min (3.2.0)

    Spezifiziert die untere Grenze des Port-Bereichs, den die JVM nutzt, um sich mit dem Wrapper zurückzuverbinden.