feat: exposing a reconnection method (#3933)

* exposing a reconnection method

* chore: adding changelog file 3933.miscellaneous.md [dependabot-skip]

* Update src/ansys/mapdl/core/mapdl_grpc.py

Co-authored-by: sourcery-ai[bot] <58596630+sourcery-ai[bot]@users.noreply.github.com>

* chore: adding changelog file 3933.miscellaneous.md [dependabot-skip]

---------

Co-authored-by: pyansys-ci-bot <[email protected]>
Co-authored-by: sourcery-ai[bot] <58596630+sourcery-ai[bot]@users.noreply.github.com>

Author: 3 people

doc/changelog.d/3933.miscellaneous.md

@@ -0,0 +1 @@
+feat: exposing a reconnection method

src/ansys/mapdl/core/mapdl_grpc.py

@@ -464,18 +464,7 @@ def __init__(
         if not self._mapdl_on_hpc and self._mapdl_process:
             self._create_process_stds_queue()
 
-        try:
-            self._multi_connect(timeout=timeout)
-        except MapdlConnectionError as err:  # pragma: no cover
-            self._post_mortem_checks()
-            self._log.debug(
-                "The error wasn't caught by the post-mortem checks.\nThe stdout is printed now:"
-            )
-            self._log.debug(self._stdout)
-
-            raise err  # Raise original error if we couldn't catch it in post-mortem analysis
-        else:
-            self._log.debug("Connection established")
+        self.reconnect_to_mapdl()
 
         # Avoiding muting when connecting to the session
         # It might trigger some errors later on if not.
@@ -527,6 +516,38 @@ def _before_run(self, _command: str) -> None:
             # For some reason the session hasn't been created
             self._create_session()
 
+    def _connect_to_mapdl(self, timeout: int):
+        """(Re)connect to an existing MAPDL instance"""
+        try:
+            self._multi_connect(timeout=timeout)
+        except MapdlConnectionError as err:  # pragma: no cover
+            self._post_mortem_checks()
+            self._log.debug(
+                "The error wasn't caught by the post-mortem checks.\nThe stdout is printed now:"
+            )
+            self._log.debug(self._stdout)
+
+            raise err  # Raise original error if we couldn't catch it in post-mortem analysis
+        else:
+            self._log.debug("Connection established")
+
+    def reconnect_to_mapdl(self, timeout: int = None):
+        """Reconnect to an already instantiated MAPDL instance.
+
+        Re-establish an stopped or crashed gRPC connection with an already alive
+        MAPDL instance. This function does not relaunch the MAPDL instance.
+
+        Parameters
+        ----------
+        timeout : int, optional
+            Timeout before raising an exception, by default None
+        """
+
+        if timeout is None:
+            timeout = self._timeout
+
+        self._connect_to_mapdl(timeout)
+
     def _create_process_stds_queue(self, process=None):
         from ansys.mapdl.core.launcher import (
             _create_queue_for_std,  # Avoid circular import error