openstack/swift
Code Issues Proposed changes

Fix logging in proxy container GET path

Browse Source 
The proxy tried to map the x-backend-sharding-state header value to
a ShardRange state, but the value is the container *db* state. The
attempted mapping would commonly fail because db state names do not
always correspond to ShardRange state names, in which the case the
fallback was to log the header value i.e. the correct outcome.

Sometimes the attempted mapping would succeed because for example
'sharded' is both a db state name and a ShardRange state name. In that
case the log message would look something like:

  "Found 1024 objects in shard (state=(70, 'sharded')), total = 1024"

i.e. the tuple of ShardRange state name and number was logged, which
was inappropriate.

Change-Id: Ic08e6e7df7162a4c1283a3ef6e67c3b21a4ce494
This commit is contained in:
Alistair Coles 2021-01-22 13:10:16 +00:00
parent d429918ed0
commit 0a230e5aed
2 changed files with 11 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
swift/proxy/controllers/container.py
View File

@ -391,23 +391,19 @@ class ContainerController(Controller):
req, shard_range.account, shard_range.container,
headers=headers, params=params)
shard_state = 'unknown'
try:
shard_state = shard_resp.headers['x-backend-sharding-state']
shard_state = ShardRange.resolve_state(shard_state)
except (AttributeError, ValueError, KeyError):
pass
sharding_state = shard_resp.headers.get('x-backend-sharding-state',
'unknown')
if objs is None:
# tolerate errors
self.app.logger.debug(
'Failed to get objects from shard (state=%s), total = %d',
shard_state, len(objects))
sharding_state, len(objects))
continue
self.app.logger.debug(
'Found %d objects in shard (state=%s), total = %d',
len(objs), shard_state, len(objs) + len(objects))
len(objs), sharding_state, len(objs) + len(objects))
if not objs:
# tolerate empty shard containers

9
test/unit/proxy/controllers/test_container.py
View File

@ -982,7 +982,7 @@ class TestContainerController(TestRingBase):
# when shrinking the final shard will return the root shard range into
# which it is shrinking
shard_resp_hdrs = {
'X-Backend-Sharding-State': 'sharded',
'X-Backend-Sharding-State': 'sharding',
'X-Container-Object-Count': 0,
'X-Container-Bytes-Used': 0,
'X-Backend-Storage-Policy-Index': 0,
@ -1028,6 +1028,11 @@ class TestContainerController(TestRingBase):
self.assertEqual(
[('a', 'c'), ('.shards_a', 'c_xyz')],
resp.request.environ.get('swift.shard_listing_history'))
lines = [line for line in self.app.logger.get_lines_for_level('debug')
if line.startswith('Found 1024 objects in shard')]
self.assertEqual(2, len(lines), lines)
self.assertIn("(state=sharded), total = 1024", lines[0]) # shard->root
self.assertIn("(state=sharding), total = 1024", lines[1]) # shard
def test_GET_sharded_container_shard_redirects_between_shards(self):
# check that if one shard redirects listing to another shard that
@ -1767,7 +1772,7 @@ class TestContainerController(TestRingBase):
'X-Backend-Storage-Policy-Index': '0'}
def _do_test_caching(self, record_type, exp_recheck_listing):
# this test gest shard ranges into cache and then reads from cache
# this test gets shard ranges into cache and then reads from cache
sharding_state = 'sharded'
self.memcache.delete_all()
self.memcache.clear_calls()