diff --git a/apps/cic-eth/cic_eth/queue/tx.py b/apps/cic-eth/cic_eth/queue/tx.py
index b6050636..9269bd89 100644
--- a/apps/cic-eth/cic_eth/queue/tx.py
+++ b/apps/cic-eth/cic_eth/queue/tx.py
@@ -500,7 +500,7 @@ def get_nonce_tx(nonce, sender, chain_id):
 
 
 # TODO: pass chain spec instead of chain id
-def get_paused_txs(status=None, sender=None, chain_id=0):
+def get_paused_txs(status=None, sender=None, chain_id=0, session=None):
     """Returns not finalized transactions that have been attempted sent without success.
 
     :param status: If set, will return transactions with this local queue status only
@@ -513,12 +513,13 @@ def get_paused_txs(status=None, sender=None, chain_id=0):
     :returns: Transactions
     :rtype: dict, with transaction hash as key, signed raw transaction as value
     """
-    session = SessionBase.create_session()
+    session = SessionBase.bind_session(session)
     q = session.query(Otx)
 
     if status != None:
         #if status == StatusEnum.PENDING or status >= StatusEnum.SENT:
         if status == StatusEnum.PENDING or status & StatusBits.IN_NETWORK or not is_alive(status):
+            SessionBase.release_session(session)
             raise ValueError('not a valid paused tx value: {}'.format(status))
         q = q.filter(Otx.status.op('&')(status.value)==status.value)
         q = q.join(TxCache)
@@ -538,12 +539,12 @@ def get_paused_txs(status=None, sender=None, chain_id=0):
             #gas += tx['gas'] * tx['gasPrice']
             txs[r.tx_hash] = r.signed_tx
 
-    session.close()
+    SessionBase.release_session(session)
 
     return txs
 
 
-def get_status_tx(status, before=None, exact=False, limit=0):
+def get_status_tx(status, before=None, exact=False, limit=0, session=None):
     """Retrieve transaction with a specific queue status.
 
     :param status: Status to match transactions with
@@ -556,7 +557,7 @@ def get_status_tx(status, before=None, exact=False, limit=0):
     :rtype: list of cic_eth.db.models.otx.Otx
     """
     txs = {}
-    session = SessionBase.create_session()
+    session = SessionBase.bind_session(session)
     q = session.query(Otx)
     q = q.join(TxCache)
     q = q.filter(TxCache.date_updated<before)
@@ -570,12 +571,12 @@ def get_status_tx(status, before=None, exact=False, limit=0):
             break
         txs[o.tx_hash] = o.signed_tx
         i += 1
-    session.close()
+    SessionBase.release_session(session)
     return txs
 
 
 # TODO: move query to model
-def get_upcoming_tx(status=StatusEnum.READYSEND, recipient=None, before=None, chain_id=0):
+def get_upcoming_tx(status=StatusEnum.READYSEND, recipient=None, before=None, chain_id=0, session=None):
     """Returns the next pending transaction, specifically the transaction with the lowest nonce, for every recipient that has pending transactions.
 
     Will omit addresses that have the LockEnum.SEND bit in Lock set.
@@ -594,7 +595,7 @@ def get_upcoming_tx(status=StatusEnum.READYSEND, recipient=None, before=None, ch
     :returns: Transactions
     :rtype: dict, with transaction hash as key, signed raw transaction as value
     """
-    session = SessionBase.create_session()
+    session = SessionBase.bind_session(session)
     q_outer = session.query(
             TxCache.sender,
             func.min(Otx.nonce).label('nonce'),
@@ -604,7 +605,7 @@ def get_upcoming_tx(status=StatusEnum.READYSEND, recipient=None, before=None, ch
     q_outer = q_outer.filter(or_(Lock.flags==None, Lock.flags.op('&')(LockEnum.SEND.value)==0))
 
     if not is_alive(status):
-        session.close()
+        SessionBase.release_session(session)
         raise ValueError('not a valid non-final tx value: {}'.format(status))
     if status == StatusEnum.PENDING:
         q_outer = q_outer.filter(Otx.status==status.value)
@@ -646,7 +647,7 @@ def get_upcoming_tx(status=StatusEnum.READYSEND, recipient=None, before=None, ch
         session.add(o)
         session.commit()
 
-    session.close()
+    SessionBase.release_session(session)
 
     return txs
 
diff --git a/apps/cic-eth/cic_eth/runnable/daemons/filters/callback.py b/apps/cic-eth/cic_eth/runnable/daemons/filters/callback.py
index 22786ee3..c70ddc72 100644
--- a/apps/cic-eth/cic_eth/runnable/daemons/filters/callback.py
+++ b/apps/cic-eth/cic_eth/runnable/daemons/filters/callback.py
@@ -82,7 +82,7 @@ class CallbackFilter(SyncFilter):
         return (transfer_type, transfer_data)
 
 
-    def filter(self, w3, tx, rcpt, chain_spec):
+    def filter(self, w3, tx, rcpt, chain_spec, session=None):
         logg.debug('applying callback filter "{}:{}"'.format(self.queue, self.method))
         chain_str = str(chain_spec)
 
diff --git a/apps/cic-eth/cic_eth/runnable/daemons/filters/gas.py b/apps/cic-eth/cic_eth/runnable/daemons/filters/gas.py
index a3cf1d32..4b312372 100644
--- a/apps/cic-eth/cic_eth/runnable/daemons/filters/gas.py
+++ b/apps/cic-eth/cic_eth/runnable/daemons/filters/gas.py
@@ -17,29 +17,31 @@ logg = logging.getLogger()
 
 class GasFilter(SyncFilter):
 
-    def __init__(self, gas_provider):
+    def __init__(self, gas_provider, queue=None):
+        self.queue = queue
         self.gas_provider = gas_provider
 
 
-    def filter(self, w3, tx, rcpt, chain_str):
+    def filter(self, w3, tx, rcpt, chain_str, session=None):
         logg.debug('applying gas filter')
         tx_hash_hex = tx.hash.hex()
         if tx['value'] > 0:
             logg.debug('gas refill tx {}'.format(tx_hash_hex))
-            session = SessionBase.create_session()
+            session = SessionBase.bind_session(session)
             q = session.query(TxCache.recipient)
             q = q.join(Otx)
             q = q.filter(Otx.tx_hash==tx_hash_hex)
             r = q.first()
 
-            session.close()
-
             if r == None:
                 logg.warning('unsolicited gas refill tx {}'.format(tx_hash_hex))
+                SessionBase.release_session(session)
                 return
 
             chain_spec = ChainSpec.from_chain_str(chain_str)
-            txs = get_paused_txs(StatusEnum.WAITFORGAS, r[0], chain_spec.chain_id())
+            txs = get_paused_txs(StatusEnum.WAITFORGAS, r[0], chain_spec.chain_id(), session=session)
+
+            SessionBase.release_session(session)
 
             if len(txs) > 0:
                 logg.info('resuming gas-in-waiting txs for {}: {}'.format(r[0], txs.keys()))
@@ -49,6 +51,6 @@ class GasFilter(SyncFilter):
                         r[0],
                         0,
                         tx_hashes_hex=list(txs.keys()),
-                        queue=queue,
+                        queue=self.queue,
                 )
                 s.apply_async()
diff --git a/apps/cic-eth/cic_eth/runnable/daemons/filters/register.py b/apps/cic-eth/cic_eth/runnable/daemons/filters/register.py
index 180cdca6..3c003d35 100644
--- a/apps/cic-eth/cic_eth/runnable/daemons/filters/register.py
+++ b/apps/cic-eth/cic_eth/runnable/daemons/filters/register.py
@@ -15,7 +15,7 @@ account_registry_add_log_hash = '0x5ed3bdd47b9af629827a8d129aa39c870b10c03f0153f
 
 class RegistrationFilter(SyncFilter):
 
-    def filter(self, w3, tx, rcpt, chain_spec):
+    def filter(self, w3, tx, rcpt, chain_spec, session=None):
         logg.debug('applying registration filter')
         registered_address = None
         for l in rcpt['logs']:
diff --git a/apps/cic-eth/cic_eth/runnable/daemons/filters/tx.py b/apps/cic-eth/cic_eth/runnable/daemons/filters/tx.py
index 6a645ff3..ceab9a10 100644
--- a/apps/cic-eth/cic_eth/runnable/daemons/filters/tx.py
+++ b/apps/cic-eth/cic_eth/runnable/daemons/filters/tx.py
@@ -6,6 +6,7 @@ import celery
 
 # local imports
 from cic_eth.db.models.otx import Otx
+from cic_eth.db.models.base import SessionBase
 from .base import SyncFilter
 
 logg = logging.getLogger()
@@ -17,15 +18,17 @@ class TxFilter(SyncFilter):
         self.queue = queue
 
 
-    def filter(self, w3, tx, rcpt, chain_spec):
+    def filter(self, w3, tx, rcpt, chain_spec, session=None):
+        session = SessionBase.bind_session(session)
         logg.debug('applying tx filter')
         tx_hash_hex = tx.hash.hex()
-        otx = Otx.load(tx_hash_hex)
+        otx = Otx.load(tx_hash_hex, session=session)
+        SessionBase.release_session(session)
         if otx == None:
             logg.debug('tx {} not found locally, skipping'.format(tx_hash_hex))
             return None
         logg.info('otx found {}'.format(otx.tx_hash))
-        s = celery.siignature(
+        s = celery.signature(
                 'cic_eth.queue.tx.set_final_status',
                 [
                     tx_hash_hex,
diff --git a/apps/cic-eth/cic_eth/runnable/daemons/manager.py b/apps/cic-eth/cic_eth/runnable/daemons/manager.py
index c6d7b836..db83460d 100644
--- a/apps/cic-eth/cic_eth/runnable/daemons/manager.py
+++ b/apps/cic-eth/cic_eth/runnable/daemons/manager.py
@@ -180,7 +180,7 @@ def main():
 
     registration_filter = RegistrationFilter()
 
-    gas_filter = GasFilter(c.gas_provider())
+    gas_filter = GasFilter(c.gas_provider(), queue)
 
     i = 0
     for syncer in syncers:
diff --git a/apps/cic-eth/cic_eth/sync/backend.py b/apps/cic-eth/cic_eth/sync/backend.py
index af58be94..eaf3ddc6 100644
--- a/apps/cic-eth/cic_eth/sync/backend.py
+++ b/apps/cic-eth/cic_eth/sync/backend.py
@@ -28,20 +28,24 @@ class SyncerBackend:
     def connect(self):
         """Loads the state of the syncer session with the given id.
         """
-        self.db_session = SessionBase.create_session()
+        if self.db_session == None:
+            self.db_session = SessionBase.create_session()
         q = self.db_session.query(BlockchainSync)
         q = q.filter(BlockchainSync.id==self.object_id)
         self.db_object = q.first()
         if self.db_object == None:
+            self.disconnect()
             raise ValueError('sync entry with id {} not found'.format(self.object_id))
 
 
     def disconnect(self):
         """Commits state of sync to backend.
         """
-        self.db_session.add(self.db_object)
-        self.db_session.commit()
-        self.db_session.close()
+        if self.db_session != None:
+            self.db_session.add(self.db_object)
+            self.db_session.commit()
+            self.db_session.close()
+            self.db_session = None
        
 
     def chain(self):
diff --git a/apps/cic-eth/cic_eth/sync/mined.py b/apps/cic-eth/cic_eth/sync/mined.py
index 616eea54..e0e165b6 100644
--- a/apps/cic-eth/cic_eth/sync/mined.py
+++ b/apps/cic-eth/cic_eth/sync/mined.py
@@ -56,7 +56,7 @@ class MinedSyncer(Syncer):
             # TODO: ensure filter loop can complete on graceful shutdown
             for f in self.filter:
                 #try:
-                task_uuid = f(w3, tx, rcpt, self.chain())
+                task_uuid = f(w3, tx, rcpt, self.chain(), self.db_session)
                 #except Exception as e:
                 #    logg.error('error in filter {} tx {}: {}'.format(f, tx_hash_hex, e))
                 #    continue