Module blocked clients cache the response in a temporary client,
the reply list in this client would be affected by the recent fix
in #7202, but when the reply is later copied into the real client,
it would have bypassed all the checks for output buffer limit, which
would have resulted in both: responding with a partial response to
the client, and also not disconnecting it at all.
c4fdf09c0 added a test that now fails with valgrind
it fails for two resons:
1) the test samples the used memory and then limits the maxmemory to
that value, but it turns out this is not atomic and on slow machines
the background cron process that clean out old query buffers reduces
the memory so that the setting doesn't cause eviction.
2) the dbsize was tested late, after reading some invalidation messages
by that time more and more keys got evicted, partially draining the
db. this is not the focus of this fix (still a known limitation)
Makes spt_init more careful with assumptions about what memory regions
may be overwritten. It will now only consider a contiguous block of argv
and envp elements and mind any gaps.
when the same consumer re-claim an entry that it already has, there's
no need to remove-and-insert if it's the same rax.
we do need to update the idle time though.
this commit only improves efficiency (doesn't change behavior).
* Add CLIENT INFO subcommand.
The output is identical to CLIENT LIST but provides a single line for
the current client only.
* Add CLIENT LIST ID [id...].
Co-authored-by: Itamar Haber <itamar@redislabs.com>
First, if the ziplist header is surely inside the ziplist, do fast path
decoding rather than the careful one.
In that case, streamline the encoding if-else chain to be executed only
once, and the encoding validity tested at the end.
encourage inlining
likely / unlikely hints for speculative execution
Assertion used _exit(1) to tell the compiler that the code after them is
not reachable and get rid of warnings.
But in some cases assertions are placed inside tight loops, and any
piece of code in them can slow down execution (code cache and other
reasons), instead using either abort() or better yet, unreachable
builtin.
If RESTORE passes successfully with full sanitization, we can't affort
to crash later on assertion due to duplicate records in a hash when
converting it form ziplist to dict.
This means that when doing full sanitization, we must make sure there
are no duplicate records in any of the collections.
when using --baseport to run two tests suite in parallel (different
folders), we need to also make sure the port used by the testsuite to
communicate with it's workers is unique. otherwise the attept to find a
free port connects to the other test suite and messes it.
maybe one day we need to attempt to bind, instead of connect when tring
to find a free port.
The test creates keys with various encodings, DUMP them, corrupt the payload
and RESTORES it.
It utilizes the recently added use-exit-on-panic config to distinguish between
asserts and segfaults.
If the restore succeeds, it runs random commands on the key to attempt to
trigger a crash.
It runs in two modes, one with deep sanitation enabled and one without.
In the first one we don't expect any assertions or segfaults, in the second one
we expect assertions, but no segfaults.
We also check for leaks and invalid reads using valgrind, and if we find them
we print the commands that lead to that issue.
Changes in the code (other than the test):
- Replace a few NPD (null pointer deference) flows and division by zero with an
assertion, so that it doesn't fail the test. (since we set the server to use
`exit` rather than `abort` on assertion).
- Fix quite a lot of flows in rdb.c that could have lead to memory leaks in
RESTORE command (since it now responds with an error rather than panic)
- Add a DEBUG flag for SET-SKIP-CHECKSUM-VALIDATION so that the test don't need
to bother with faking a valid checksum
- Remove a pile of code in serverLogObjectDebugInfo which is actually unsafe to
run in the crash report (see comments in the code)
- fix a missing boundary check in lzf_decompress
test suite infra improvements:
- be able to run valgrind checks before the process terminates
- rotate log files when restarting servers
- improve stream rdb encoding test to include more types of stream metadata
- add test to cover various ziplist encoding entries (although it does
look like the stress test above it is able to find some too
- add another test for ziplist encoding for hash with full sanitization
- add similar ziplist encoding tests for list
When loading an encoded payload we will at least do a shallow validation to
check that the size that's encoded in the payload matches the size of the
allocation.
This let's us later use this encoded size to make sure the various offsets
inside encoded payload don't reach outside the allocation, if they do, we'll
assert/panic, but at least we won't segfault or smear memory.
We can also do 'deep' validation which runs on all the records of the encoded
payload and validates that they don't contain invalid offsets. This lets us
detect corruptions early and reject a RESTORE command rather than accepting
it and asserting (crashing) later when accessing that payload via some command.
configuration:
- adding ACL flag skip-sanitize-payload
- adding config sanitize-dump-payload [yes/no/clients]
For now, we don't have a good way to ensure MIGRATE in cluster resharding isn't
being slowed down by these sanitation, so i'm setting the default value to `no`,
but later on it should be set to `clients` by default.
changes:
- changing rdbReportError not to `exit` in RESTORE command
- adding a new stat to be able to later check if cluster MIGRATE isn't being
slowed down by sanitation.
When client tracking is enabled signalModifiedKey can increase memory usage,
this can cause the loop in performEvictions to keep running since it was measuring
the memory usage impact of signalModifiedKey.
The section that measures the memory impact of the eviction should be just on dbDelete,
excluding keyspace notification, client tracking, and propagation to AOF and replicas.
This resolves part of the problem described in #8069
p.s. fix took 1 minute, test took about 3 hours to write.
One way this was happening is when a module issued an RM_Call which would inject MULTI.
If the module command that does that was itself issued by something else that already did
added MULTI (e.g. another module, or a Lua script), it would have caused nested MULTI.
In fact the MULTI state in the client or the MULTI_EMITTED flag in the context isn't
the right indication that we need to propagate MULTI or not, because on a nested calls
(possibly a module action called by a keyspace event of another module action), these
flags aren't retained / reflected.
instead there's now a global propagate_in_transaction flag for that.
in addition to that, we now have a global in_eval and in_exec flags, to serve the flags
of RM_GetContextFlags, since their dependence on the current client is wrong for the same
reasons mentioned above.
As we know, redis may reject user's requests or evict some keys if
used memory is over maxmemory. Dictionaries expanding may make
things worse, some big dictionaries, such as main db and expires dict,
may eat huge memory at once for allocating a new big hash table and be
far more than maxmemory after expanding.
There are related issues: #4213#4583
More details, when expand dict in redis, we will allocate a new big
ht[1] that generally is double of ht[0], The size of ht[1] will be
very big if ht[0] already is big. For db dict, if we have more than
64 million keys, we need to cost 1GB for ht[1] when dict expands.
If the sum of used memory and new hash table of dict needed exceeds
maxmemory, we shouldn't allow the dict to expand. Because, if we
enable keys eviction, we still couldn't add much more keys after
eviction and rehashing, what's worse, redis will keep less keys when
redis only remains a little memory for storing new hash table instead
of users' data. Moreover users can't write data in redis if disable
keys eviction.
What this commit changed ?
Add a new member function expandAllowed for dict type, it provide a way
for caller to allow expand or not. We expose two parameters for this
function: more memory needed for expanding and dict current load factor,
users can implement a function to make a decision by them.
For main db dict and expires dict type, these dictionaries may be very
big and cost huge memory for expanding, so we implement a judgement
function: we can stop dict to expand provisionally if used memory will
be over maxmemory after dict expands, but to guarantee the performance
of redis, we still allow dict to expand if dict load factor exceeds the
safe load factor.
Add test cases to verify we don't allow main db to expand when left
memory is not enough, so that avoid keys eviction.
Other changes:
For new hash table size when expand. Before this commit, the size is
that double used of dict and later _dictNextPower. Actually we aim to
control a dict load factor between 0.5 and 1.0. Now we replace *2 with
+1, since the first check is that used >= size, the outcome of before
will usually be the same as _dictNextPower(used+1). The only case where
it'll differ is when dict_can_resize is false during fork, so that later
the _dictNextPower(used*2) will cause the dict to jump to *4 (i.e.
_dictNextPower(1025*2) will return 4096).
Fix rehash test cases due to changing algorithm of new hash table size
when expand.
In the iterator for these functions, we'll traverse the sorted sets
in a reversed way so that largest elements come first. We prefer
this order because it's optimized for insertion in a skiplist, which
is the destination of the elements being iterated in there functions.
When replica diskless-load type is swapdb in cluster mode, we didn't backup
keys to slots map, so we will lose keys to slots map if fail to sync.
Now we backup keys to slots map at first, and restore it properly when fail.
This commit includes a refactory/cleanup of the backups mechanism (moving it to db.c and re-structuring it a bit).
Co-authored-by: Oran Agra <oran@redislabs.com>
As described in redis-benchamrk help message 'The test names are the same as the ones produced as output.', In redis-benchmark output, we can only see PING_BULK, but the cmd `redis-benchmark -t ping_bulk` is not supported. We have to run it with ping_mbulk which is not user friendly.
SELECT used to read the index into a `long` variable, and then pass it to a function
that takes an `int`, possibly causing an overflow before the range check.
Now all these commands use better and cleaner range check, and that also results in
a slight change of the error response in case of an invalid database index.
SELECT:
in the past it would have returned either `-ERR invalid DB index` (if not a number),
or `-ERR DB index is out of range` (if not between 1..16 or alike).
now it'll return either `-ERR value is out of range` (if not a number), or
`-ERR value is out of range, value must between -2147483648 and 2147483647`
(if not in the range for an int), or `-ERR DB index is out of range`
(if not between 0..16 or alike)
MOVE:
in the past it would only fail with `-ERR index out of range` no matter the reason.
now return the same errors as the new ones for SELECT mentioned above.
(i.e. unlike for SELECT even for a value like 17 we changed the error message)
COPY:
doesn't really matter how it behaved in the past (new command), new behavior is
like the above two.
Fixes#7923.
This PR appropriates the special `&` symbol (because `@` and `*` are taken),
followed by a literal value or pattern for describing the Pub/Sub patterns that
an ACL user can interact with. It is similar to the existing key patterns
mechanism in function (additive) and implementation (copy-pasta). It also adds
the allchannels and resetchannels ACL keywords, naturally.
The default user is given allchannels permissions, whereas new users get
whatever is defined by the acl-pubsub-default configuration directive. For
backward compatibility in 6.2, the default of this directive is allchannels but
this is likely to be changed to resetchannels in the next major version for
stronger default security settings.
Unless allchannels is set for the user, channel access permissions are checked
as follows :
* Calls to both PUBLISH and SUBSCRIBE will fail unless a pattern matching the
argumentative channel name(s) exists for the user.
* Calls to PSUBSCRIBE will fail unless the pattern(s) provided as an argument
literally exist(s) in the user's list.
Such failures are logged to the ACL log.
Runtime changes to channel permissions for a user with existing subscribing
clients cause said clients to disconnect unless the new permissions permit the
connections to continue. Note, however, that PSUBSCRIBErs' patterns are matched
literally, so given the change bar:* -> b*, pattern subscribers to bar:* will be
disconnected.
Notes/questions:
* UNSUBSCRIBE, PUNSUBSCRIBE and PUBSUB remain unprotected due to lack of reasons
for touching them.
when performing the and operation, if the output is 0, we can jump out of the loop.
when performing an or operation, if the output is 0xff, we can jump out of the loop.
