double timeout each try

@karnem this feature doubles the timeout each try while trying to send or retrieve a constant from database

cal_tools/cal_tools/tools.py

@@ -237,7 +237,7 @@ already_printed = {}
 
 def get_from_db(device, constant, condition, empty_constant,
                 cal_db_interface, creation_time=None,
-                verbosity=1, timeout=30000, ntries=120, meta_only=True,
+                verbosity=1, timeout=30000, ntries=7, meta_only=True,
                 version_info=False):
     """
     Return calibration constants and metadata requested from CalDB
@@ -250,6 +250,8 @@ def get_from_db(device, constant, condition, empty_constant,
     :param creation_time: Latest time for constant to be created
     :param verbosity: Level of verbosity (0 - silent)
     :param timeout: Timeout for zmq request
+    ntries is set to 7 so that if the timeout started at 30s last timeout
+    will be ~ 1h.
     :param ntries: number of tries to contact the database
     :param meta_only: Retrieve only metadata via ZMQ. Constants are taken
         directly from the h5 file on maxwell.
@@ -288,6 +290,7 @@ def get_from_db(device, constant, condition, empty_constant,
                 break
             except zmq.error.Again:
                 ntries -= 1
+                timeout *= 2
                 sleep(np.random.randint(30))
             except Exception as e:
                 if verbosity > 0:
@@ -314,7 +317,7 @@ def get_from_db(device, constant, condition, empty_constant,
 
 def send_to_db(device, constant, condition, file_loc,
                cal_db_interface, creation_time=None,
-               verbosity=1, timeout=30000, ntries=120, doraise=False):
+               verbosity=1, timeout=30000, ntries=7, doraise=False):
     """
     Return calibration constants and metadata requested from CalDB
 
@@ -326,7 +329,9 @@ def send_to_db(device, constant, condition, file_loc,
     :param creation_time: Latest time for constant to be created
     :param verbosity: Level of verbosity (0 - silent)
     :param timeout: Timeout for zmq request
-    :param ntries: number of tries to contact the database
+    :param ntries: number of tries to contact the database,
+    ntries is set to 7 so that if the timeout started at 30s last timeout
+    will be ~ 1h.
     :param doraise: if True raise errors during communication with DB
     """
     from iCalibrationDB import ConstantMetaData, Versions
@@ -354,6 +359,7 @@ def send_to_db(device, constant, condition, file_loc,
                 break
             except zmq.error.Again:
                 ntries -= 1
+                timeout *= 2
                 sleep(np.random.randint(30))
                 if ntries == 0 and doraise:
                     raise

[Karim Ahmed]

ntries has been decreased to 7 times to reach ~1h if timeout started with 30s

[Karim Ahmed]

what is this doing and would it be beneficial in get_from_db also?