zmq test: fix sync-up by matching notification to generated block #21310
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
fc1bcab to
b387970
Compare
jonatack
reviewed
Feb 27, 2021
Member
jonatack
left a comment
There was a problem hiding this comment.
Approach ACK, thanks for working on this.
some suggestions
-# Helper class for setting up a ZMQ test via the "sync up" procedure.
-# Generates a block on the specified node on instantiation and provides a method to check
-# whether a ZMQ notification matches, i.e. the event was caused by this generated block.
-# Assumes that a notification either contains the generated block's hash, it's
-# (coinbase) transaction id, the raw block or raw transaction data.
class ZMQTestSetupBlock:
+ """Helper class for setting up a ZMQ test via the "sync up" procedure.
+ Generates a block on the specified node on instantiation and provides a
+ method to check whether a ZMQ notification matches, i.e. the event was
+ caused by this generated block. Assumes that a notification either contains
+ the generated block's hash, it's (coinbase) transaction id, the raw block or
+ raw transaction data.
+ """
+
def __init__(self, node):
self.block_hash = node.generate(1)[0]
coinbase = node.getblock(self.block_hash, 2)['tx'][0]
@@ -76,10 +79,12 @@ class ZMQTestSetupBlock:
self.raw_block = node.getblock(self.block_hash, 0)
def caused_notification(self, notification):
- return self.block_hash in notification or \
- self.tx_hash in notification or \
- self.raw_block in notification or \
- self.raw_tx in notification
+ return (
+ self.block_hash in notification
+ or self.tx_hash in notification
+ or self.raw_block in notification
+ or self.raw_tx in notification
+ )
class ZMQTest (BitcoinTestFramework):
@@ -136,7 +141,7 @@ class ZMQTest (BitcoinTestFramework):
for sub in subscribers:
try:
while not test_block.caused_notification(sub.receive().hex()):
- self.log.debug("Ignoring sync-up notification for previoulsy generated block.")
+ self.log.debug("Ignoring sync-up notification for previously generated block.")
except zmq.error.Again:
self.log.debug("Didn't receive sync-up notification, trying again.")
recv_failed = True
@@ -361,7 +366,7 @@ class ZMQTest (BitcoinTestFramework):
block_count = self.nodes[0].getblockcount()
best_hash = self.nodes[0].getbestblockhash()
self.nodes[0].invalidateblock(best_hash)
- sleep(2) # Bit of room to make sure transaction things happened
+ sleep(2) # Bit of room to make sure transaction things happened
# Make sure getrawmempool mempool_sequence results aren't "queued" but immediately reflective
# of the time they were gathered.
@@ -410,8 +415,8 @@ class ZMQTest (BitcoinTestFramework):
assert_equal(label, "A")
# More transactions to be simply mined
for i in range(len(more_tx)):
- assert_equal((more_tx[i], "A", mempool_seq), seq.receive_sequence())
- mempool_seq += 1
+ assert_equal((more_tx[i], "A", mempool_seq), seq.receive_sequence())
+ mempool_seq += 1
# Bumped by rbf
assert_equal((orig_txid, "R", mempool_seq), seq.receive_sequence())
mempool_seq += 1
@@ -426,7 +431,7 @@ class ZMQTest (BitcoinTestFramework):
assert_equal((orig_txid_2, "A", mempool_seq), seq.receive_sequence())
mempool_seq += 1
self.nodes[0].generatetoaddress(1, ADDRESS_BCRT1_UNSPENDABLE)
- self.sync_all() # want to make sure we didn't break "consensus" for other tests
+ self.sync_all() # want to make sure we didn't break "consensus" for other tests
def test_mempool_sync(self):It turned out that the "sync up" procedure of repeatedly generating a
block and waiting for a notification once with timeout is too naive in
its current form, as the following scenario could happen:
- generate block A
- receive notification, timeout happens -> repeat procedure
- generate block B
- node publishes block A notification
- receive notification, we receive the one caused by block A
-> sync-up procedure is completed
- node publishes block B
- the actual test starts
- on the first notification reception, one caused by block B is received,
rather than the one actually caused by test code, leading to failure
This change ensures that after each test block generation, we wait for
the notification that is actually caused by that block and ignore others
from possibly earlier blocks.
Co-authored-by: Jon Atack <jon@atack.com>
b387970 to
8a8c638
Compare
Contributor
Author
|
Force-pushed with all changes suggested by @jonatack (thanks for catching the typo and the style fixups, looks much better now! 🚀 ). |
Member
|
Concept ACK 8a8c638 Thanks! |
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
4 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This is a follow-up PR for #21008, fixes #21216.
In the course of investigating the problem with jnewbery (analyzing the Cirrus log https://cirrus-ci.com/task/4660108304056320), it turned out that the "sync up" procedure of repeatedly generating a block and waiting for a notification with timeout is too brittle in its current form, as the following scenario could happen:
This change in the PR ensures that after each test block generation, we wait for the notification that is actually caused by that block and ignore others from possibly earlier blocks. The matching is kind of ugly, it assumes that one out of four components in the block is contained in the notification: the block hash, the tx id, the raw block data or the raw transaction data. (Unfortunately we have to support all publisher topics.)
I'm aware that this is quite a lot of code now only for establishing a robust test setup. OTOH I wouldn't know of a better method right now, suggestions are very welcome.
Note for potential reviewers: for both reproducing the issue on master branch and verifying on PR branch, one can simply generate two blocks in the sync-up procedure rather than one.