Improved locking mechanism. Removing former sendlogs before next disp…

…atching retry.

common/helper.py

@@ -91,7 +91,7 @@ class FileLock:
     def __init__(self, path_for_lockfile: Path):
         self.lockCreated = True
         self.lockfile = path_for_lockfile
-        self.lockfile.touch()
+        self.lockfile.touch(exist_ok=False)
 
     # Destructor to ensure that the lock file gets deleted
     # if the calling function is left somewhere as result

dispatch/send.py

@@ -121,12 +121,16 @@ def execute(
             logger.error(error_message)            
             send_event(m_events.PROCESSING, severity.WARNING, error_message)
 
-        # Create a .sending file to indicate that this folder is being sent,
-        # otherwise the dispatcher would pick it up again if the transfer is
-        # still going on
+        # Create a .processing file to indicate that this folder is being sent,
+        # otherwise another dispatcher instance would pick it up again 
         lock_file = Path(source_folder) / mercure_names.PROCESSING
+
+        # Double check that the case has not been picked up by another instance already
+        if lock_file.exists():
+            logger.info(f"Case {source_folder} already processed by other instance")
+            return
         try:
-            lock_file.touch()
+            lock_file.touch(exist_ok=False)
         except:
             # TODO: Put a limit on these error messages -- log will run full at some point
             send_event(m_events.PROCESSING, severity.ERROR, f"Error sending {uid} to {target_name}")
@@ -146,6 +150,18 @@ def execute(
             _move_sent_directory(source_folder, error_folder)
             _trigger_notification(task_content.info, mercure_events.ERROR)
 
+        # Check if a sendlog file from a previous try exists. If so, remove it
+        sendlog = Path(source_folder) / mercure_names.SENDLOG
+        if sendlog.exists():
+            try:
+                sendlog.unlink()
+            except:
+                send_event(m_events.PROCESSING, severity.ERROR, f"Error sending {uid} to {target_name}")
+                error_message = f"Unable to remove former sendlog {sendlog}"
+                send_series_event(s_events.ERROR, uid, 0, target_name, error_message)
+                logger.exception(error_message)
+                return
+
         logger.debug(f"Running command {command}")
         logger.info(f"Sending {source_folder} to target {target_name}")
         try:               

dispatch/status.py

@@ -40,11 +40,6 @@ def is_ready_for_sending(folder) -> Optional[Task]:
     return None
 
 
-def has_been_send(folder) -> bool:
-    """Checks if the given folder has already been sent."""
-    return (Path(folder) / mercure_names.SENDLOG).exists()
-
-
 def is_target_json_valid(folder) -> Optional[Task]:
     """
     Checks if the task.json file exists and is valid. Returns the content 

dispatcher.py

@@ -19,7 +19,7 @@
 import common.helper as helper
 import common.monitor as monitor
 from common.constants import mercure_names
-from dispatch.status import has_been_send, is_ready_for_sending
+from dispatch.status import is_ready_for_sending
 from dispatch.send import execute
 from common.constants import mercure_defs
 
@@ -96,7 +96,7 @@ def dispatch(args) -> None:
                 logger.info("Dispatching resumed")
 
         # Now process the folders that are ready for dispatching
-        if entry.is_dir() and not has_been_send(entry) and is_ready_for_sending(entry):
+        if entry.is_dir() and is_ready_for_sending(entry):
             logger.info(f"Sending folder {entry}")
             execute(Path(entry), success_folder, error_folder, retry_max, retry_delay)
 

process/process_series.py

@@ -235,7 +235,7 @@ def process_series(folder) -> None:
     lock = None
     try:
         try:
-            lock_file.touch()
+            lock_file.touch(exist_ok=False)
             # lock = helper.FileLock(lock_file)
         except Exception as e:
             # Can't create lock file, so something must be seriously wrong
@@ -348,7 +348,7 @@ def move_results(
         logger.error(f"Folder already contains lockfile {folder}/" + mercure_names.LOCK)
         return
     try:
-        lock_file.touch()
+        lock_file.touch(exist_ok=False)
     except:
         logger.info(f"Error locking folder to be moved {folder}")
         logger.error(traceback.format_exc())

tests/dispatch/test_status.py

@@ -1,7 +1,7 @@
 import json
 from common.types import Task
 
-from dispatch.status import has_been_send, is_ready_for_sending, is_target_json_valid
+from dispatch.status import is_ready_for_sending, is_target_json_valid
 from common.constants import mercure_names
 
 pytest_plugins = ("pyfakefs",)
@@ -43,17 +43,6 @@ def test_is_read_for_sending(fs):
     assert is_ready_for_sending("/var/data")
 
 
-def test_has_been_send(fs):
-    fs.create_dir("/var/data/")
-    fs.create_file("/var/data/" + mercure_names.SENDLOG)
-    assert has_been_send("/var/data/")
-
-
-def test_has_been_send_not(fs):
-    fs.create_dir("/var/data/")
-    assert not has_been_send("/var/data/")
-
-
 def test_read_target(fs):
     target = {"info": dummy_info, "dispatch": {"target_name": "test_target"}}
     fs.create_file("/var/data/" + mercure_names.TASKFILE, contents=json.dumps(target))

tests/test_processor.py

@@ -142,7 +142,7 @@ def fake_processor(tag=None, meta=None, **kwargs):
         logger.info(k)
     for k in Path("/var/success").rglob("*"):
         logger.info(k)
-    # (processor_path / ".complete").touch()
+    # (processor_path / ".complete").touch(exist_ok=False)
     # processor.run_processor()
 
     assert (Path("/var/success") / processor_path.name).exists(), f"{processor_path.name} missing from success dir"

webinterface/templates/configuration.html

@@ -41,7 +41,7 @@ <h5 class="title is-5 configtitle"><i class="fas fa-server has-text-success"></i
                         <td>Accept Compressed Images:</td>
                         <td>{{config['accept_compressed_images']}}
                             {% if config['accept_compressed_images']=='True' %}
-                            <a href="https://mercure-imaging.org/docs/advanced.html" target="_blank" title="This setting can be problematic. Carefully read the documentation"><i class="fas fa-exclamation-circle has-text-warning" style="margin-left: 1px;"></i></a>
+                            <a href="https://mercure-imaging.org/docs/advanced.html#additional-settings" target="_blank" title="This setting can be problematic. Carefully read the documentation"><i class="fas fa-exclamation-circle has-text-warning" style="margin-left: 1px;"></i></a>
                             {% endif %}
                         </td>
                     </tr>