redict/tests/unit/moduleapi/blockedclient.tcl
Meir Shpilraien (Spielrein) 61baabd8d5
Fix crash on RM_Call with script mode. (#10886)
The PR fixes 2 issues:

### RM_Call crash on script mode

`RM_Call` can potentially be called from a background thread where `server.current_client`
are not set. In such case we get a crash on `NULL` dereference.
The fix is to check first if `server.current_client` is `NULL`, if it does we should
verify disc errors and readonly replica as we do to any normal clients (no masters nor AOF).

### RM_Call block OOM commands when not needed

Again `RM_Call` can be executed on a background thread using a `ThreadSafeCtx`.
In such case `server.pre_command_oom_state` can be irrelevant and should not be
considered when check OOM state. This cause OOM commands to be blocked when
not necessarily needed.

In such case, check the actual used memory (and not the cached value). Notice that in
order to know if the cached value can be used, we check that the ctx that was used on
the `RM_Call` is a ThreadSafeCtx. Module writer can potentially abuse the API and use
ThreadSafeCtx on the main thread. We consider this as a API miss used.
2022-06-21 10:01:13 +03:00

254 lines
8.8 KiB
Tcl

set testmodule [file normalize tests/modules/blockedclient.so]
start_server {tags {"modules"}} {
r module load $testmodule
test {Locked GIL acquisition} {
assert_match "OK" [r acquire_gil]
}
test {Locked GIL acquisition during multi} {
r multi
r acquire_gil
assert_equal {{Blocked client is not supported inside multi}} [r exec]
}
test {Locked GIL acquisition from RM_Call} {
assert_equal {Blocked client is not allowed} [r do_rm_call acquire_gil]
}
test {Blocking command are not block the client on RM_Call} {
r lpush l test
assert_equal [r do_rm_call blpop l 0] {l test}
r lpush l test
assert_equal [r do_rm_call brpop l 0] {l test}
r lpush l1 test
assert_equal [r do_rm_call brpoplpush l1 l2 0] {test}
assert_equal [r do_rm_call brpop l2 0] {l2 test}
r lpush l1 test
assert_equal [r do_rm_call blmove l1 l2 LEFT LEFT 0] {test}
assert_equal [r do_rm_call brpop l2 0] {l2 test}
r ZADD zset1 0 a 1 b 2 c
assert_equal [r do_rm_call bzpopmin zset1 0] {zset1 a 0}
assert_equal [r do_rm_call bzpopmax zset1 0] {zset1 c 2}
r xgroup create s g $ MKSTREAM
r xadd s * foo bar
assert {[r do_rm_call xread BLOCK 0 STREAMS s 0-0] ne {}}
assert {[r do_rm_call xreadgroup group g c BLOCK 0 STREAMS s >] ne {}}
assert {[r do_rm_call blpop empty_list 0] eq {}}
assert {[r do_rm_call brpop empty_list 0] eq {}}
assert {[r do_rm_call brpoplpush empty_list1 empty_list2 0] eq {}}
assert {[r do_rm_call blmove empty_list1 empty_list2 LEFT LEFT 0] eq {}}
assert {[r do_rm_call bzpopmin empty_zset 0] eq {}}
assert {[r do_rm_call bzpopmax empty_zset 0] eq {}}
r xgroup create empty_stream g $ MKSTREAM
assert {[r do_rm_call xread BLOCK 0 STREAMS empty_stream $] eq {}}
assert {[r do_rm_call xreadgroup group g c BLOCK 0 STREAMS empty_stream >] eq {}}
}
test {Monitor disallow inside RM_Call} {
set e {}
catch {
r do_rm_call monitor
} e
set e
} {*ERR*DENY BLOCKING*}
test {subscribe disallow inside RM_Call} {
set e {}
catch {
r do_rm_call subscribe x
} e
set e
} {*ERR*DENY BLOCKING*}
test {RM_Call from blocked client} {
r hset hash foo bar
r do_bg_rm_call hgetall hash
} {foo bar}
test {RM_Call from blocked client with script mode} {
r do_bg_rm_call_format S hset k foo bar
} {1}
test {RM_Call from blocked client with oom mode} {
r config set maxmemory 1
# will set server.pre_command_oom_state to 1
assert_error {OOM command not allowed*} {r hset hash foo bar}
r config set maxmemory 0
# now its should be OK to call OOM commands
r do_bg_rm_call_format M hset k1 foo bar
} {1} {needs:config-maxmemory}
test {RESP version carries through to blocked client} {
for {set client_proto 2} {$client_proto <= 3} {incr client_proto} {
r hello $client_proto
r readraw 1
set ret [r do_fake_bg_true]
if {$client_proto == 2} {
assert_equal $ret {:1}
} else {
assert_equal $ret "#t"
}
r readraw 0
}
}
foreach call_type {nested normal} {
test "Busy module command - $call_type" {
set busy_time_limit 50
set old_time_limit [lindex [r config get busy-reply-threshold] 1]
r config set busy-reply-threshold $busy_time_limit
set rd [redis_deferring_client]
# run command that blocks until released
set start [clock clicks -milliseconds]
if {$call_type == "nested"} {
$rd do_rm_call slow_fg_command 0
} else {
$rd slow_fg_command 0
}
$rd flush
# send another command after the blocked one, to make sure we don't attempt to process it
$rd ping
$rd flush
# make sure we get BUSY error, and that we didn't get it too early
assert_error {*BUSY Slow module operation*} {r ping}
assert_morethan_equal [expr [clock clicks -milliseconds]-$start] $busy_time_limit
# abort the blocking operation
r stop_slow_fg_command
wait_for_condition 50 100 {
[catch {r ping} e] == 0
} else {
fail "Failed waiting for busy command to end"
}
assert_equal [$rd read] "1"
assert_equal [$rd read] "PONG"
# run command that blocks for 200ms
set start [clock clicks -milliseconds]
if {$call_type == "nested"} {
$rd do_rm_call slow_fg_command 200000
} else {
$rd slow_fg_command 200000
}
$rd flush
after 10 ;# try to make sure redis started running the command before we proceed
# make sure we didn't get BUSY error, it simply blocked till the command was done
r ping
assert_morethan_equal [expr [clock clicks -milliseconds]-$start] 200
$rd read
$rd close
r config set busy-reply-threshold $old_time_limit
}
}
test {RM_Call from blocked client} {
set busy_time_limit 50
set old_time_limit [lindex [r config get busy-reply-threshold] 1]
r config set busy-reply-threshold $busy_time_limit
# trigger slow operation
r set_slow_bg_operation 1
r hset hash foo bar
set rd [redis_deferring_client]
set start [clock clicks -milliseconds]
$rd do_bg_rm_call hgetall hash
# send another command after the blocked one, to make sure we don't attempt to process it
$rd ping
$rd flush
# wait till we know we're blocked inside the module
wait_for_condition 50 100 {
[r is_in_slow_bg_operation] eq 1
} else {
fail "Failed waiting for slow operation to start"
}
# make sure we get BUSY error, and that we didn't get here too early
assert_error {*BUSY Slow module operation*} {r ping}
assert_morethan [expr [clock clicks -milliseconds]-$start] $busy_time_limit
# abort the blocking operation
r set_slow_bg_operation 0
wait_for_condition 50 100 {
[r is_in_slow_bg_operation] eq 0
} else {
fail "Failed waiting for slow operation to stop"
}
assert_equal [r ping] {PONG}
r config set busy-reply-threshold $old_time_limit
assert_equal [$rd read] {foo bar}
assert_equal [$rd read] {PONG}
$rd close
}
test {blocked client reaches client output buffer limit} {
r hset hash big [string repeat x 50000]
r hset hash bada [string repeat x 50000]
r hset hash boom [string repeat x 50000]
r config set client-output-buffer-limit {normal 100000 0 0}
r client setname myclient
catch {r do_bg_rm_call hgetall hash} e
assert_match "*I/O error*" $e
reconnect
set clients [r client list]
assert_no_match "*name=myclient*" $clients
}
test {module client error stats} {
r config resetstat
# simple module command that replies with string error
assert_error "ERR unknown command 'hgetalllll', with args beginning with:" {r do_rm_call hgetalllll}
assert_equal [errorrstat ERR r] {count=1}
# simple module command that replies with string error
assert_error "ERR unknown subcommand 'bla'. Try CONFIG HELP." {r do_rm_call config bla}
assert_equal [errorrstat ERR r] {count=2}
# module command that replies with string error from bg thread
assert_error "NULL reply returned" {r do_bg_rm_call hgetalllll}
assert_equal [errorrstat NULL r] {count=1}
# module command that returns an arity error
r do_rm_call set x x
assert_error "ERR wrong number of arguments for 'do_rm_call' command" {r do_rm_call}
assert_equal [errorrstat ERR r] {count=3}
# RM_Call that propagates an error
assert_error "WRONGTYPE*" {r do_rm_call hgetall x}
assert_equal [errorrstat WRONGTYPE r] {count=1}
assert_match {*calls=1,*,rejected_calls=0,failed_calls=1} [cmdrstat hgetall r]
# RM_Call from bg thread that propagates an error
assert_error "WRONGTYPE*" {r do_bg_rm_call hgetall x}
assert_equal [errorrstat WRONGTYPE r] {count=2}
assert_match {*calls=2,*,rejected_calls=0,failed_calls=2} [cmdrstat hgetall r]
assert_equal [s total_error_replies] 6
assert_match {*calls=5,*,rejected_calls=0,failed_calls=4} [cmdrstat do_rm_call r]
assert_match {*calls=2,*,rejected_calls=0,failed_calls=2} [cmdrstat do_bg_rm_call r]
}
test "Unload the module - blockedclient" {
assert_equal {OK} [r module unload blockedclient]
}
}