## Current state
1. Lua has its own parser that handles parsing `reds.call` replies and translates them
to Lua objects that can be used by the user Lua code. The parser partially handles
resp3 (missing big number, verbatim, attribute, ...)
2. Modules have their own parser that handles parsing `RM_Call` replies and translates
them to RedisModuleCallReply objects. The parser does not support resp3.
In addition, in the future, we want to add Redis Function (#8693) that will probably
support more languages. At some point maintaining so many parsers will stop
scaling (bug fixes and protocol changes will need to be applied on all of them).
We will probably end up with different parsers that support different parts of the
resp protocol (like we already have today with Lua and modules)
## PR Changes
This PR attempt to unified the reply parsing of Lua and modules (and in the future
Redis Function) by introducing a new parser unit (`resp_parser.c`). The new parser
handles parsing the reply and calls different callbacks to allow the users (another
unit that uses the parser, i.e, Lua, modules, or Redis Function) to analyze the reply.
### Lua API Additions
The code that handles reply parsing on `scripting.c` was removed. Instead, it uses
the resp_parser to parse and create a Lua object out of the reply. As mentioned
above the Lua parser did not handle parsing big numbers, verbatim, and attribute.
The new parser can handle those and so Lua also gets it for free.
Those are translated to Lua objects in the following way:
1. Big Number - Lua table `{'big_number':'<str representation for big number>'}`
2. Verbatim - Lua table `{'verbatim_string':{'format':'<verbatim format>', 'string':'<verbatim string value>'}}`
3. Attribute - currently ignored and not expose to the Lua parser, another issue will be open to decide how to expose it.
Tests were added to check resp3 reply parsing on Lua
### Modules API Additions
The reply parsing code on `module.c` was also removed and the new resp_parser is used instead.
In addition, the RedisModuleCallReply was also extracted to a separate unit located on `call_reply.c`
(in the future, this unit will also be used by Redis Function). A nice side effect of unified parsing is
that modules now also support resp3. Resp3 can be enabled by giving `3` as a parameter to the
fmt argument of `RM_Call`. It is also possible to give `0`, which will indicate an auto mode. i.e, Redis
will automatically chose the reply protocol base on the current client set on the RedisModuleCtx
(this mode will mostly be used when the module want to pass the reply to the client as is).
In addition, the following RedisModuleAPI were added to allow analyzing resp3 replies:
* New RedisModuleCallReply types:
* `REDISMODULE_REPLY_MAP`
* `REDISMODULE_REPLY_SET`
* `REDISMODULE_REPLY_BOOL`
* `REDISMODULE_REPLY_DOUBLE`
* `REDISMODULE_REPLY_BIG_NUMBER`
* `REDISMODULE_REPLY_VERBATIM_STRING`
* `REDISMODULE_REPLY_ATTRIBUTE`
* New RedisModuleAPI:
* `RedisModule_CallReplyDouble` - getting double value from resp3 double reply
* `RedisModule_CallReplyBool` - getting boolean value from resp3 boolean reply
* `RedisModule_CallReplyBigNumber` - getting big number value from resp3 big number reply
* `RedisModule_CallReplyVerbatim` - getting format and value from resp3 verbatim reply
* `RedisModule_CallReplySetElement` - getting element from resp3 set reply
* `RedisModule_CallReplyMapElement` - getting key and value from resp3 map reply
* `RedisModule_CallReplyAttribute` - getting a reply attribute
* `RedisModule_CallReplyAttributeElement` - getting key and value from resp3 attribute reply
* New context flags:
* `REDISMODULE_CTX_FLAGS_RESP3` - indicate that the client is using resp3
Tests were added to check the new RedisModuleAPI
### Modules API Changes
* RM_ReplyWithCallReply might return REDISMODULE_ERR if the given CallReply is in resp3
but the client expects resp2. This is not a breaking change because in order to get a resp3
CallReply one needs to specifically specify `3` as a parameter to the fmt argument of
`RM_Call` (as mentioned above).
Tests were added to check this change
### More small Additions
* Added `debug set-disable-deny-scripts` that allows to turn on and off the commands no-script
flag protection. This is used by the Lua resp3 tests so it will be possible to run `debug protocol`
and check the resp3 parsing code.
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: Yossi Gottlieb <yossigo@gmail.com>
This PR adds a spell checker CI action that will fail future PRs if they introduce typos and spelling mistakes.
This spell checker is based on blacklist of common spelling mistakes, so it will not catch everything,
but at least it is also unlikely to cause false positives.
Besides that, the PR also fixes many spelling mistakes and types, not all are a result of the spell checker we use.
Here's a summary of other changes:
1. Scanned the entire source code and fixes all sorts of typos and spelling mistakes (including missing or extra spaces).
2. Outdated function / variable / argument names in comments
3. Fix outdated keyspace masks error log when we check `config.notify-keyspace-events` in loadServerConfigFromString.
4. Trim the white space at the end of line in `module.c`. Check: https://github.com/redis/redis/pull/7751
5. Some outdated https link URLs.
6. Fix some outdated comment. Such as:
- In README: about the rdb, we used to said create a `thread`, change to `process`
- dbRandomKey function coment (about the dictGetRandomKey, change to dictGetFairRandomKey)
- notifyKeyspaceEvent fucntion comment (add type arg)
- Some others minor fix in comment (Most of them are incorrectly quoted by variable names)
7. Modified the error log so that users can easily distinguish between TCP and TLS in `changeBindAddr`
When we allocate a client struct with 16k reply buffer, the allocator we may give us 20K,
This commit makes use of that extra space.
Additionally, it tries to store whatever it can from the reply into the static 'buf' before
allocating a new node for the reply list.
Add publish channel permissions check in processCommand.
processCommand didn't check publish channel permissions, so we can
queue a publish command in a transaction. But when exec the transaction,
it will fail with -NOPERM.
We also union keys/commands/channels permissions check togegher in
ACLCheckAllPerm. Remove pubsubCheckACLPermissionsOrReply in
publishCommand/subscribeCommand/psubscribeCommand. Always
check permissions in processCommand/execCommand/
luaRedisGenericCommand.
pcall function runs another LUA function in protected mode, this means
that any error will be caught by this function and will not stop the LUA
execution. The script kill mechanism uses error to stop the running script.
Scripts that uses pcall can catch the error raise by the script kill mechanism,
this will cause a script like this to be unkillable:
local f = function()
while 1 do
redis.call('ping')
end
end
while 1 do
pcall(f)
end
The fix is, when we want to kill the script, we set the hook function to be invoked
after each line. This will promise that the execution will get another
error before it is able to enter the pcall function again.
1. moduleReplicateMultiIfNeeded should use server.in_eval like
moduleHandlePropagationAfterCommandCallback
2. server.in_eval could have been set to 1 and not reset back
to 0 (a lot of missed early-exits after in_eval is already 1)
Note: The new assertions in processCommand cover (2) and I added
two module tests to cover (1)
Implications:
If an EVAL that failed (and thus left server.in_eval=1) runs before a module
command that replicates, the replication stream will contain MULTI (because
moduleReplicateMultiIfNeeded used to check server.lua_caller which is NULL
at this point) but not EXEC (because server.in_eval==1)
This only affects modules as module.c the only user of server.in_eval.
Affects versions 6.2.0, 6.2.1
* Adds ASYNC and SYNC arguments to SCRIPT FLUSH
* Adds SYNC argument to FLUSHDB and FLUSHALL
* Adds new config to control the default behavior of FLUSHDB, FLUSHALL and SCRIPT FLUASH.
the new behavior is as follows:
* FLUSH[ALL|DB],SCRIPT FLUSH: Determine sync or async according to the
value of lazyfree-lazy-user-flush.
* FLUSH[ALL|DB],SCRIPT FLUSH ASYNC: Always flushes the database in an async manner.
* FLUSH[ALL|DB],SCRIPT FLUSH SYNC: Always flushes the database in a sync manner.
When a Lua script returns a map to redis (a feature which was added in
redis 6 together with RESP3), it would have returned the value first and
the key second.
If the client was using RESP2, it was getting them out of order, and if
the client was in RESP3, it was getting a map of value => key.
This was happening regardless of the Lua script using redis.setresp(3)
or not.
This also affects a case where the script was returning a map which it got
from from redis by doing something like: redis.setresp(3); return redis.call()
This fix is a breaking change for redis 6.0 users who happened to rely
on the wrong order (either ones that used redis.setresp(3), or ones that
returned a map explicitly).
This commit also includes other two changes in the tests:
1. The test suite now handles RESP3 maps as dicts rather than nested
lists
2. Remove some redundant (duplicate) tests from tracking.tcl
* man-like consistent long formatting
* Uppercases commands, subcommands and options
* Adds 'HELP' to HELP for all
* Lexicographical order
* Uses value notation and other .md likeness
* Moves const char *help to top
* Keeps it under 80 chars
* Misc help typos, consistent conjuctioning (i.e return and not returns)
* Uses addReplySubcommandSyntaxError(c) all over
Signed-off-by: Itamar Haber <itamar@redislabs.com>
Recently efaf09ee4 started using addReplyErrorSds in place of
addReplySds the later takes ownership of the string but the former did
not.
This introduced memory leaks when a script returns an error to redis,
and also in clusterRedirectClient (two new usages of
addReplyErrorSds which was mostly unused till now.
This commit chagnes two thanks.
1. change addReplyErrorSds to take ownership of the error string.
2. scripting.c doesn't actually need to use addReplyErrorSds, it's a
perfect match for addReplyErrorFormat (replaces newlines with spaces)
In the distant history there was only the read flag for commands, and whatever
command that didn't have the read flag was a write one.
Then we added the write flag, but some portions of the code still used !read
Also some commands that don't work on the keyspace at all, still have the read
flag.
Changes in this commit:
1. remove the read-only flag from TIME, ECHO, ROLE and LASTSAVE
2. EXEC command used to decides if it should propagate a MULTI by looking at
the command flags (!read & !admin).
When i was about to change it to look at the write flag instead, i realized
that this would cause it not to propagate a MULTI for PUBLISH, EVAL, and
SCRIPT, all 3 are not marked as either a read command or a write one (as
they should), but all 3 are calling forceCommandPropagation.
So instead of introducing a new flag to denote a command that "writes" but
not into the keyspace, and still needs propagation, i decided to rely on
the forceCommandPropagation, and just fix the code to propagate MULTI when
needed rather than depending on the command flags at all.
The implication of my change then is that now it won't decide to propagate
MULTI when it sees one of these: SELECT, PING, INFO, COMMAND, TIME and
other commands which are neither read nor write.
3. Changing getNodeByQuery and clusterRedirectBlockedClientIfNeeded in
cluster.c to look at !write rather than read flag.
This should have no implications, since these code paths are only reachable
for commands which access keys, and these are always marked as either read
or write.
This commit improve MULTI propagation tests, for modules and a bunch of
other special cases, all of which used to pass already before that commit.
the only one that test change that uncovered a change of behavior is the
one that DELs a non-existing key, it used to propagate an empty
multi-exec block, and no longer does.
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.
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.
Blocking command should not be used with MULTI, LUA, and RM_Call. This is because,
the caller, who executes the command in this context, expects a reply.
Today, LUA and MULTI have a special (and different) treatment to blocking commands:
LUA - Most commands are marked with no-script flag which are checked when executing
and command from LUA, commands that are not marked (like XREAD) verify that their
blocking mode is not used inside LUA (by checking the CLIENT_LUA client flag).
MULTI - Command that is going to block, first verify that the client is not inside
multi (by checking the CLIENT_MULTI client flag). If the client is inside multi, they
return a result which is a match to the empty key with no timeout (for example blpop
inside MULTI will act as lpop)
For modules that perform RM_Call with blocking command, the returned results type is
REDISMODULE_REPLY_UNKNOWN and the caller can not really know what happened.
Disadvantages of the current state are:
No unified approach, LUA, MULTI, and RM_Call, each has a different treatment
Module can not safely execute blocking command (and get reply or error).
Though It is true that modules are not like LUA or MULTI and should be smarter not
to execute blocking commands on RM_Call, sometimes you want to execute a command base
on client input (for example if you create a module that provides a new scripting
language like javascript or python).
While modules (on modules command) can check for REDISMODULE_CTX_FLAGS_LUA or
REDISMODULE_CTX_FLAGS_MULTI to know not to block the client, there is no way to
check if the command came from another module using RM_Call. So there is no way
for a module to know not to block another module RM_Call execution.
This commit adds a way to unify the treatment for blocking clients by introducing
a new CLIENT_DENY_BLOCKING client flag. On LUA, MULTI, and RM_Call the new flag
turned on to signify that the client should not be blocked. A blocking command
verifies that the flag is turned off before blocking. If a blocking command sees
that the CLIENT_DENY_BLOCKING flag is on, it's not blocking and return results
which are matches to empty key with no timeout (as MULTI does today).
The new flag is checked on the following commands:
List blocking commands: BLPOP, BRPOP, BRPOPLPUSH, BLMOVE,
Zset blocking commands: BZPOPMIN, BZPOPMAX
Stream blocking commands: XREAD, XREADGROUP
SUBSCRIBE, PSUBSCRIBE, MONITOR
In addition, the new flag is turned on inside the AOF client, we do not want to
block the AOF client to prevent deadlocks and commands ordering issues (and there
is also an existing assert in the code that verifies it).
To keep backward compatibility on LUA, all the no-script flags on existing commands
were kept untouched. In addition, a LUA special treatment on XREAD and XREADGROUP was kept.
To keep backward compatibility on MULTI (which today allows SUBSCRIBE, and PSUBSCRIBE).
We added a special treatment on those commands to allow executing them on MULTI.
The only backward compatibility issue that this PR introduces is that now MONITOR
is not allowed inside MULTI.
Tests were added to verify blocking commands are not blocking the client on LUA, MULTI,
or RM_Call. Tests were added to verify the module can check for CLIENT_DENY_BLOCKING flag.
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: Itamar Haber <itamar@redislabs.com>
During long running scripts or loading RDB/AOF, we may need to do some
defragging. Since processEventsWhileBlocked is called periodically at
unknown intervals, and many cron jobs either depend on run_with_period
(including active defrag), or rely on being called at server.hz rate
(i.e. active defrag knows ho much time to run by looking at server.hz),
the whileBlockedCron may have to run a loop triggering the cron jobs in it
(currently only active defrag) several times.
Other changes:
- Adding a test for defrag during aof loading.
- Changing key-load-delay config to take negative values for fractions
of a microsecond sleep
Checking OOM by `getMaxMemoryState` inside script might get different result
with `freeMemoryIfNeededAndSafe` at script start, because lua stack and
arguments also consume memory.
This leads to memory `borderline` when memory grows near server.maxmemory:
- `freeMemoryIfNeededAndSafe` at script start detects no OOM, no memory freed
- `getMaxMemoryState` inside script detects OOM, script aborted
We solve this 'borderline' issue by saving OOM state at script start to get
stable lua OOM state.
related to issue #6565 and #5250.
Random command like SPOP with count is replicated as
some SREM operations, and store them in also_propagate
array to propagate after the call, but this would break
atomicity.
To keep the command's atomicity, wrap also_propagate
array with MULTI/EXEC.
To avoid nested MULTI/EXEC, we check the lua_caller's flag,
if we are in the MULTI context we flag the lua_client as
CLIENT_MULTI, but it's not enough we shoud flag lua_client
as CLIENT_MULTI after redis.replicate_commands() immediately
or the first write command after redis.replicate_commands()
cannot know it's in an transaction, I know the missing CLIENT_MULTI
doesn't have any effect now, but it's a real bug and we should fix
it, in case someday we allow some dangerous command like BLPOP.
* Introduce a connection abstraction layer for all socket operations and
integrate it across the code base.
* Provide an optional TLS connections implementation based on OpenSSL.
* Pull a newer version of hiredis with TLS support.
* Tests, redis-cli updates for TLS support.
since the slowlog and other means that can help you detect the bad script
are only exposed after the script is done. it might be a good idea to at least
print the script name (sha) to the log when it timeouts.
