--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Common/RetryDatabaseFactory.cpp	Fri Apr 02 19:27:32 2021 +0200
@@ -0,0 +1,64 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2021 Osimis S.A., Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Affero General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#include "RetryDatabaseFactory.h"
+
+#include <Logging.h>
+#include <OrthancException.h>
+
+#include <boost/thread.hpp>
+
+
+namespace OrthancDatabases
+{
+  IDatabase* RetryDatabaseFactory::Open()
+  {
+    unsigned int count = 0;
+    
+    for (;;)
+    {
+      try
+      {
+        return TryOpen();
+      }
+      catch (Orthanc::OrthancException& e)
+      {
+        if (e.GetErrorCode() == Orthanc::ErrorCode_DatabaseUnavailable)
+        {
+          count ++;
+
+          if (count <= maxConnectionRetries_)
+          {
+            LOG(WARNING) << "Database is currently unavailable, retrying...";
+            boost::this_thread::sleep(boost::posix_time::seconds(connectionRetryInterval_));
+            continue;
+          }
+          else
+          {
+            LOG(ERROR) << "Timeout when connecting to the database, giving up";
+          }
+        }
+
+        throw;
+      }
+    }
+  }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Common/RetryDatabaseFactory.h	Fri Apr 02 19:27:32 2021 +0200
@@ -0,0 +1,49 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2021 Osimis S.A., Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Affero General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#pragma once
+
+#include "IDatabaseFactory.h"
+
+#include <Compatibility.h>
+
+namespace OrthancDatabases
+{
+  class RetryDatabaseFactory : public IDatabaseFactory
+  {
+  private:
+    unsigned int  maxConnectionRetries_;
+    unsigned int  connectionRetryInterval_;
+
+  protected:
+    virtual IDatabase* TryOpen() = 0;
+    
+  public:
+    RetryDatabaseFactory(unsigned int maxConnectionRetries,
+                         unsigned int connectionRetryInterval) :
+      maxConnectionRetries_(maxConnectionRetries),
+      connectionRetryInterval_(connectionRetryInterval)
+    {
+    }
+
+    virtual IDatabase* Open() ORTHANC_OVERRIDE;
+  };
+}