Add missing lock file

CHANGELOG

@@ -1,3 +1,10 @@
+- 0.2.2
+	* Fix missing symbol crashes related to race conditions
+- 0.2.1
+	* Receive removed race checks from chainqueue
+- 0.2.0
+	* primitive race condition handling between fs access of sync and queue
+	* re-enable throttling based on in-flight transaction count
 - 0.1.2
 	* add settings object
 - 0.1.0

chaind/adapters/base.py

@@ -1,10 +1,27 @@
+# standard imports
+import logging
+import time
+
 # external imports
 from chainqueue import Store as QueueStore
 
+# local imports
+from chaind.lock import StoreLock
+
+logg = logging.getLogger(__name__)
+
 
 class ChaindAdapter:
 
     def __init__(self, chain_spec, state_store, index_store, counter_store, cache_adapter, dispatcher, cache=None, pending_retry_threshold=0, error_retry_threshold=0):
         self.cache_adapter = cache_adapter
         self.dispatcher = dispatcher
-        self.store = QueueStore(chain_spec, state_store, index_store, counter_store, cache=cache)
+        store_lock = StoreLock()
+        while True:
+            try:
+                self.store = QueueStore(chain_spec, state_store, index_store, counter_store, cache=cache)
+                break
+            except FileNotFoundError as e:
+                logg.debug('queuestore instantiation failed, possible race condition (will try again): {}'.format(e))
+                store_lock.again()
+                continue

chaind/adapters/fs.py

@@ -1,6 +1,7 @@
 # standard imports
 import logging
 import os
+import time
 
 # external imports
 from chainlib.error import RPCException
@@ -10,12 +11,15 @@ from chainqueue.store.fs import (
         IndexStore,
         CounterStore,
         )
-from chainqueue.error import BackendIntegrityError
 from shep.store.file import SimpleFileStoreFactory
-from shep.error import StateInvalid
+from shep.error import (
+        StateInvalid,
+        StateLockedKey,
+        )
 
 # local imports
 from .base import ChaindAdapter
+from chaind.lock import StoreLock
 
 logg = logging.getLogger(__name__)
 
@@ -23,7 +27,7 @@ logg = logging.getLogger(__name__)
 class ChaindFsAdapter(ChaindAdapter):
 
     def __init__(self, chain_spec, path, cache_adapter, dispatcher, cache=None, pending_retry_threshold=0, error_retry_threshold=0, digest_bytes=32, event_callback=None):
-        factory = SimpleFileStoreFactory(path).add
+        factory = SimpleFileStoreFactory(path, use_lock=True).add
         state_store = Status(factory, allow_invalid=True, event_callback=event_callback)
         index_path = os.path.join(path, 'tx')
         index_store = IndexStore(index_path, digest_bytes=digest_bytes)
@@ -38,21 +42,29 @@ class ChaindFsAdapter(ChaindAdapter):
 
     def get(self, tx_hash):
         v = None
-        try:
+        store_lock = StoreLock()
-            v = self.store.get(tx_hash)
+        while True:
-        except StateInvalid as e:
+            try:
-            logg.error('I am just a simple syncer and do not know how to handle the state which the tx {} is in: {}'.format(tx_hash, e))
+                v = self.store.get(tx_hash)
-            return None
+                break
-        except FileNotFoundError:
+            except StateInvalid as e:
-            pass
+                logg.error('I am just a simple syncer and do not know how to handle the state which the tx {} is in: {}'.format(tx_hash, e))
-        if v ==None:
+                return None
-            raise BackendIntegrityError(tx_hash)
+            except FileNotFoundError as e:
+                logg.debug('queuestore get {} failed, possible race condition (will try again): {}'.format(tx_hash, e))
+                store_lock.again()
+                continue
+            except StateLockedKey as e:
+                logg.debug('queuestore get {} failed, possible race condition (will try again): {}'.format(tx_hash, e))
+                store_lock.again()
+                continue
+
         return v[1]
 
 
     def upcoming(self, limit=0):
         real_limit = 0
-        in_flight = 0
+        in_flight = []
         if limit > 0:
             in_flight = self.store.by_state(state=self.store.IN_NETWORK, not_state=self.store.FINAL)
             real_limit = limit - len(in_flight)
@@ -95,7 +107,22 @@ class ChaindFsAdapter(ChaindAdapter):
 
 
     def dispatch(self, tx_hash):
-        entry = self.store.send_start(tx_hash)
+        entry = None
+
+        store_lock = StoreLock()
+        while True:
+            try:
+                entry = self.store.send_start(tx_hash)
+                break
+            except FileNotFoundError as e:
+                logg.debug('dispatch failed to find {} in backend, will try again: {}'.format(tx_hash, e))
+                store_lock.again()
+                continue
+            except StateLockedKey as e:
+                logg.debug('dispatch failed to find {} in backend, will try again: {}'.format(tx_hash, e))
+                store_lock.again()
+                continue
+
         tx_wire = entry.serialize()
 
         r = None
@@ -105,5 +132,18 @@ class ChaindFsAdapter(ChaindAdapter):
             self.store.fail(tx_hash)
             return False
 
-        self.store.send_end(tx_hash)
+        store_lock = StoreLock()
+        while True:
+            try:
+                self.store.send_end(tx_hash)
+                break
+            except FileNotFoundError as e:
+                logg.debug('dispatch failed to find {} in backend, will try again: {}'.format(tx_hash, e))
+                store_lock.again(e)
+                continue
+            except StateLockedKey as e:
+                logg.debug('dispatch failed to find {} in backend, will try again: {}'.format(tx_hash, e))
+                store_lock.again(e)
+                continue
+
         return True

chaind/error.py

@@ -20,3 +20,7 @@ class ClientInputError(ValueError):
 
 class QueueLockError(Exception):
     pass
+
+
+class BackendError(Exception):
+    pass

chaind/filter.py

@@ -5,22 +5,22 @@ import time
 # external imports
 from chainlib.status import Status as TxStatus
 from chainsyncer.filter import SyncFilter
-from chainqueue.error import (
+from chainqueue.error import NotLocalTxError
-        NotLocalTxError,
-        BackendIntegrityError,
-        )
 from chaind.adapters.fs import ChaindFsAdapter
+from shep.error import StateLockedKey
 
 # local imports
-from .error import QueueLockError
+from .error import (
+        QueueLockError,
+        BackendError,
+        )
+from chaind.lock import StoreLock
 
 logg = logging.getLogger(__name__)
 
 
 class StateFilter(SyncFilter):
 
-    delay_limit = 3.0
-
     def __init__(self, chain_spec, adapter_path, tx_adapter, throttler=None):
         self.chain_spec = chain_spec
         self.adapter_path = adapter_path
@@ -30,8 +30,9 @@ class StateFilter(SyncFilter):
 
     def filter(self, conn, block, tx, session=None):
         cache_tx = None
-        for i in range(3):
+        store_lock = StoreLock()
-            queue_adapter = None
+        queue_adapter = None
+        while True:
             try:
                 queue_adapter = ChaindFsAdapter(
                     self.chain_spec,
@@ -39,28 +40,31 @@ class StateFilter(SyncFilter):
                     self.tx_adapter,
                     None,
                     )
-            except BackendIntegrityError as e:
+            except BackendError as e:
                 logg.error('adapter instantiation failed: {}, one more try'.format(e))
+                store_lock.again()
                 continue
 
+            store_lock.reset()
+
             try:
                 cache_tx = queue_adapter.get(tx.hash)
+                break
             except NotLocalTxError:
                 logg.debug('skipping not local transaction {}'.format(tx.hash))
                 return False
-            except BackendIntegrityError as e:
+            except BackendError as e:
                 logg.error('adapter instantiation failed: {}, one more try'.format(e))
+                queue_adapter = None
+                store_lock.again()
                 continue
 
-            break
-
         if cache_tx == None:
             raise NotLocalTxError(tx.hash)
 
-        delay = 0.01
+        store_lock = StoreLock()
+        queue_lock = StoreLock(error=QueueLockError)
         while True:
-            if delay > self.delay_limit:
-                raise QueueLockError('The queue lock for tx {} seems to be stuck. Human meddling needed.'.format(tx.hash))
             try:
                 if tx.status == TxStatus.SUCCESS:
                     queue_adapter.succeed(block, tx)
@@ -69,8 +73,21 @@ class StateFilter(SyncFilter):
                 break
             except QueueLockError as e:
                 logg.debug('queue item {} is blocked, will retry: {}'.format(tx.hash, e))
-                time.sleep(delay)
+                queue_lock.again()
-                delay *= 2
+            except FileNotFoundError as e:
+                logg.debug('queue item {} not found, possible race condition, will retry: {}'.format(tx.hash, e))
+                store_lock.again()
+                continue
+            except NotLocalTxError as e:
+                logg.debug('queue item {} not found, possible race condition, will retry: {}'.format(tx.hash, e))
+                store_lock.again()
+                continue
+            except StateLockedKey as e:
+                logg.debug('queue item {} not found, possible race condition, will retry: {}'.format(tx.hash, e))
+                store_lock.again()
+                continue
+
+        logg.info('filter registered {} for {} in {}'.format(tx.status.name, tx.hash, block))
 
         if self.throttler != None:
             self.throttler.dec(tx.hash)

chaind/lock.py

@@ -0,0 +1,34 @@
+# standard imports
+import time
+
+# local imports
+from .error import BackendError
+
+BASE_DELAY = 0.01
+BASE_DELAY_LIMIT = 3.0
+
+
+class StoreLock:
+
+    def __init__(self, delay=BASE_DELAY, delay_limit=BASE_DELAY_LIMIT, error=BackendError, description=None):
+        self.base_delay = delay
+        self.delay = delay
+        self.delay_limit = delay_limit
+        self.error = error
+        self.description = description
+
+    
+    def again(self, e=None):
+        if self.delay > self.delay_limit:
+            err = None
+            if e != None:
+                err = str(e)
+            else:
+                err = self.description
+            raise self.error(err)
+        time.sleep(self.delay)
+        self.delay *= 2
+
+
+    def reset(self):
+        self.delay = self.base_delay

chaind/session.py

@@ -8,12 +8,14 @@ import stat
 from hexathon import strip_0x
 
 # local imports
-from chaind.error import (
+from .error import (
         NothingToDoError,
         ClientGoneError,
         ClientBlockError,
         ClientInputError,
         )
+from .lock import StoreLock
+from .error import BackendError
 
 logg = logging.getLogger(__name__)
 
@@ -59,7 +61,16 @@ class SessionController:
 
 
     def process(self, conn):
-        r = self.processor(self.chain_spec, self.adapter, conn)
+        state_lock = StoreLock()
+        r = None
+        while True:
+            try:
+                r = self.processor(self.chain_spec, self.adapter, conn)
+                break
+            except BackendError as e:
+                state_lock.again(e)
+                continue
+                
         if r > 0:
             self.srv.settimeout(0.1)
         else:

requirements.txt

@@ -1,5 +1,5 @@
 chainlib~=0.1.1
-chainqueue~=0.1.6
+chainqueue~=0.1.8
 chainsyncer~=0.4.3
 confini~=0.6.0
 funga~=0.5.2

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = chaind
-version = 0.2.0
+version = 0.2.2
 description = Base package for chain queue service
 author = Louis Holbrook
 author_email = dev@holbrook.no

tests/test_fs.py

@@ -74,7 +74,7 @@ class TestChaindFs(TestChaindFsBase):
         data = os.urandom(128).hex()
         hsh = self.adapter.put(data)
         
-        fltr = StateFilter(self.adapter)
+        fltr = StateFilter(self.chain_spec, self.path, MockCacheAdapter)
         tx = MockTx(hsh)
         fltr.filter(None, None, tx)
 
@@ -85,7 +85,7 @@ class TestChaindFs(TestChaindFsBase):
         data = os.urandom(128).hex()
         hsh = self.adapter.put(data)
         
-        fltr = StateFilter(self.adapter)
+        fltr = StateFilter(self.chain_spec, self.path, MockCacheAdapter)
         tx = MockTx(hsh, TxStatus.ERROR)
         fltr.filter(None, None, tx)