redis/tests/unit/client-eviction.tcl

587 lines
21 KiB
Tcl

tags {"external:skip logreqres:skip"} {
# Get info about a redis client connection:
# name - name of client we want to query
# f - field name from "CLIENT LIST" we want to get
proc client_field {name f} {
set clients [split [string trim [r client list]] "\r\n"]
set c [lsearch -inline $clients *name=$name*]
if {![regexp $f=(\[a-zA-Z0-9-\]+) $c - res]} {
error "no client named $name found with field $f"
}
return $res
}
proc client_exists {name} {
if {[catch { client_field $name tot-mem } e]} {
return false
}
return true
}
proc gen_client {} {
set rr [redis_client]
set name "tst_[randstring 4 4 simplealpha]"
$rr client setname $name
assert {[client_exists $name]}
return [list $rr $name]
}
# Sum a value across all redis client connections:
# f - the field name from "CLIENT LIST" we want to sum
proc clients_sum {f} {
set sum 0
set clients [split [string trim [r client list]] "\r\n"]
foreach c $clients {
if {![regexp $f=(\[a-zA-Z0-9-\]+) $c - res]} {
error "field $f not found in $c"
}
incr sum $res
}
return $sum
}
proc mb {v} {
return [expr $v * 1024 * 1024]
}
proc kb {v} {
return [expr $v * 1024]
}
start_server {} {
set maxmemory_clients 3000000
r config set maxmemory-clients $maxmemory_clients
test "client evicted due to large argv" {
r flushdb
lassign [gen_client] rr cname
# Attempt a large multi-bulk command under eviction limit
$rr mset k v k2 [string repeat v 1000000]
assert_equal [$rr get k] v
# Attempt another command, now causing client eviction
catch { $rr mset k v k2 [string repeat v $maxmemory_clients] } e
assert {![client_exists $cname]}
$rr close
}
test "client evicted due to large query buf" {
r flushdb
lassign [gen_client] rr cname
# Attempt to fill the query buff without completing the argument above the limit, causing client eviction
catch {
$rr write [join [list "*1\r\n\$$maxmemory_clients\r\n" [string repeat v $maxmemory_clients]] ""]
$rr flush
$rr read
} e
assert {![client_exists $cname]}
$rr close
}
test "client evicted due to percentage of maxmemory" {
set maxmemory [mb 6]
r config set maxmemory $maxmemory
# Set client eviction threshold to 7% of maxmemory
set maxmemory_clients_p 7
r config set maxmemory-clients $maxmemory_clients_p%
r flushdb
set maxmemory_clients_actual [expr $maxmemory * $maxmemory_clients_p / 100]
lassign [gen_client] rr cname
# Attempt to fill the query buff with only half the percentage threshold verify we're not disconnected
set n [expr $maxmemory_clients_actual / 2]
$rr write [join [list "*1\r\n\$$n\r\n" [string repeat v $n]] ""]
$rr flush
set tot_mem [client_field $cname tot-mem]
assert {$tot_mem >= $n && $tot_mem < $maxmemory_clients_actual}
# Attempt to fill the query buff with the percentage threshold of maxmemory and verify we're evicted
$rr close
lassign [gen_client] rr cname
catch {
$rr write [join [list "*1\r\n\$$maxmemory_clients_actual\r\n" [string repeat v $maxmemory_clients_actual]] ""]
$rr flush
} e
assert {![client_exists $cname]}
$rr close
# Restore settings
r config set maxmemory 0
r config set maxmemory-clients $maxmemory_clients
}
test "client evicted due to large multi buf" {
r flushdb
lassign [gen_client] rr cname
# Attempt a multi-exec where sum of commands is less than maxmemory_clients
$rr multi
$rr set k [string repeat v [expr $maxmemory_clients / 4]]
$rr set k [string repeat v [expr $maxmemory_clients / 4]]
assert_equal [$rr exec] {OK OK}
# Attempt a multi-exec where sum of commands is more than maxmemory_clients, causing client eviction
$rr multi
catch {
for {set j 0} {$j < 5} {incr j} {
$rr set k [string repeat v [expr $maxmemory_clients / 4]]
}
} e
assert {![client_exists $cname]}
$rr close
}
test "client evicted due to watched key list" {
r flushdb
set rr [redis_client]
# Since watched key list is a small overhead this test uses a minimal maxmemory-clients config
set temp_maxmemory_clients 200000
r config set maxmemory-clients $temp_maxmemory_clients
# Append watched keys until list maxes out maxmemory clients and causes client eviction
catch {
for {set j 0} {$j < $temp_maxmemory_clients} {incr j} {
$rr watch $j
}
} e
assert_match {I/O error reading reply} $e
$rr close
# Restore config for next tests
r config set maxmemory-clients $maxmemory_clients
}
test "client evicted due to pubsub subscriptions" {
r flushdb
# Since pubsub subscriptions cause a small overhead this test uses a minimal maxmemory-clients config
set temp_maxmemory_clients 200000
r config set maxmemory-clients $temp_maxmemory_clients
# Test eviction due to pubsub patterns
set rr [redis_client]
# Add patterns until list maxes out maxmemory clients and causes client eviction
catch {
for {set j 0} {$j < $temp_maxmemory_clients} {incr j} {
$rr psubscribe $j
}
} e
assert_match {I/O error reading reply} $e
$rr close
# Test eviction due to pubsub channels
set rr [redis_client]
# Subscribe to global channels until list maxes out maxmemory clients and causes client eviction
catch {
for {set j 0} {$j < $temp_maxmemory_clients} {incr j} {
$rr subscribe $j
}
} e
assert_match {I/O error reading reply} $e
$rr close
# Test eviction due to sharded pubsub channels
set rr [redis_client]
# Subscribe to sharded pubsub channels until list maxes out maxmemory clients and causes client eviction
catch {
for {set j 0} {$j < $temp_maxmemory_clients} {incr j} {
$rr ssubscribe $j
}
} e
assert_match {I/O error reading reply} $e
$rr close
# Restore config for next tests
r config set maxmemory-clients $maxmemory_clients
}
test "client evicted due to tracking redirection" {
r flushdb
set rr [redis_client]
set redirected_c [redis_client]
$redirected_c client setname redirected_client
set redir_id [$redirected_c client id]
$redirected_c SUBSCRIBE __redis__:invalidate
$rr client tracking on redirect $redir_id bcast
# Use a big key name to fill the redirected tracking client's buffer quickly
set key_length [expr 1024*200]
set long_key [string repeat k $key_length]
# Use a script so we won't need to pass the long key name when dirtying it in the loop
set script_sha [$rr script load "redis.call('incr', '$long_key')"]
# Pause serverCron so it won't update memory usage since we're testing the update logic when
# writing tracking redirection output
r debug pause-cron 1
# Read and write to same (long) key until redirected_client's buffers cause it to be evicted
catch {
while true {
set mem [client_field redirected_client tot-mem]
assert {$mem < $maxmemory_clients}
$rr evalsha $script_sha 0
}
} e
assert_match {no client named redirected_client found*} $e
r debug pause-cron 0
$rr close
$redirected_c close
} {0} {needs:debug}
test "client evicted due to client tracking prefixes" {
r flushdb
set rr [redis_client]
# Since tracking prefixes list is a small overhead this test uses a minimal maxmemory-clients config
set temp_maxmemory_clients 200000
r config set maxmemory-clients $temp_maxmemory_clients
# Append tracking prefixes until list maxes out maxmemory clients and causes client eviction
# Combine more prefixes in each command to speed up the test. Because we did not actually count
# the memory usage of all prefixes, see getClientMemoryUsage, so we can not use larger prefixes
# to speed up the test here.
catch {
for {set j 0} {$j < $temp_maxmemory_clients} {incr j} {
$rr client tracking on prefix [format a%09s $j] prefix [format b%09s $j] prefix [format c%09s $j] bcast
}
} e
assert_match {I/O error reading reply} $e
$rr close
# Restore config for next tests
r config set maxmemory-clients $maxmemory_clients
}
test "client evicted due to output buf" {
r flushdb
r setrange k 200000 v
set rr [redis_deferring_client]
$rr client setname test_client
$rr flush
assert {[$rr read] == "OK"}
# Attempt a large response under eviction limit
$rr get k
$rr flush
assert {[string length [$rr read]] == 200001}
set mem [client_field test_client tot-mem]
assert {$mem < $maxmemory_clients}
# Fill output buff in loop without reading it and make sure
# we're eventually disconnected, but before reaching maxmemory_clients
while true {
if { [catch {
set mem [client_field test_client tot-mem]
assert {$mem < $maxmemory_clients}
$rr get k
$rr flush
} e]} {
assert {![client_exists test_client]}
break
}
}
$rr close
}
foreach {no_evict} {on off} {
test "client no-evict $no_evict" {
r flushdb
r client setname control
r client no-evict on ;# Avoid evicting the main connection
lassign [gen_client] rr cname
$rr client no-evict $no_evict
# Overflow maxmemory-clients
set qbsize [expr {$maxmemory_clients + 1}]
if {[catch {
$rr write [join [list "*1\r\n\$$qbsize\r\n" [string repeat v $qbsize]] ""]
$rr flush
wait_for_condition 200 10 {
[client_field $cname qbuf] == $qbsize
} else {
fail "Failed to fill qbuf for test"
}
} e] && $no_evict == off} {
assert {![client_exists $cname]}
} elseif {$no_evict == on} {
assert {[client_field $cname tot-mem] > $maxmemory_clients}
}
$rr close
}
}
}
start_server {} {
set server_pid [s process_id]
set maxmemory_clients [mb 10]
set obuf_limit [mb 3]
r config set maxmemory-clients $maxmemory_clients
r config set client-output-buffer-limit "normal $obuf_limit 0 0"
test "avoid client eviction when client is freed by output buffer limit" {
r flushdb
set obuf_size [expr {$obuf_limit + [mb 1]}]
r setrange k $obuf_size v
set rr1 [redis_client]
$rr1 client setname "qbuf-client"
set rr2 [redis_deferring_client]
$rr2 client setname "obuf-client1"
assert_equal [$rr2 read] OK
set rr3 [redis_deferring_client]
$rr3 client setname "obuf-client2"
assert_equal [$rr3 read] OK
# Occupy client's query buff with less than output buffer limit left to exceed maxmemory-clients
set qbsize [expr {$maxmemory_clients - $obuf_size}]
$rr1 write [join [list "*1\r\n\$$qbsize\r\n" [string repeat v $qbsize]] ""]
$rr1 flush
# Wait for qbuff to be as expected
wait_for_condition 200 10 {
[client_field qbuf-client qbuf] == $qbsize
} else {
fail "Failed to fill qbuf for test"
}
# Make the other two obuf-clients pass obuf limit and also pass maxmemory-clients
# We use two obuf-clients to make sure that even if client eviction is attempted
# between two command processing (with no sleep) we don't perform any client eviction
# because the obuf limit is enforced with precedence.
pause_process $server_pid
$rr2 get k
$rr2 flush
$rr3 get k
$rr3 flush
resume_process $server_pid
r ping ;# make sure a full event loop cycle is processed before issuing CLIENT LIST
# Validate obuf-clients were disconnected (because of obuf limit)
catch {client_field obuf-client1 name} e
assert_match {no client named obuf-client1 found*} $e
catch {client_field obuf-client2 name} e
assert_match {no client named obuf-client2 found*} $e
# Validate qbuf-client is still connected and wasn't evicted
assert_equal [client_field qbuf-client name] {qbuf-client}
$rr1 close
$rr2 close
$rr3 close
}
}
start_server {} {
test "decrease maxmemory-clients causes client eviction" {
set maxmemory_clients [mb 4]
set client_count 10
set qbsize [expr ($maxmemory_clients - [mb 1]) / $client_count]
r config set maxmemory-clients $maxmemory_clients
# Make multiple clients consume together roughly 1mb less than maxmemory_clients
set rrs {}
for {set j 0} {$j < $client_count} {incr j} {
set rr [redis_client]
lappend rrs $rr
$rr client setname client$j
$rr write [join [list "*2\r\n\$$qbsize\r\n" [string repeat v $qbsize]] ""]
$rr flush
wait_for_condition 200 10 {
[client_field client$j qbuf] >= $qbsize
} else {
fail "Failed to fill qbuf for test"
}
}
# Make sure all clients are still connected
set connected_clients [llength [lsearch -all [split [string trim [r client list]] "\r\n"] *name=client*]]
assert {$connected_clients == $client_count}
# Decrease maxmemory_clients and expect client eviction
r config set maxmemory-clients [expr $maxmemory_clients / 2]
set connected_clients [llength [lsearch -all [split [string trim [r client list]] "\r\n"] *name=client*]]
assert {$connected_clients > 0 && $connected_clients < $client_count}
foreach rr $rrs {$rr close}
}
}
start_server {} {
test "evict clients only until below limit" {
set client_count 10
set client_mem [mb 1]
r debug replybuffer resizing 0
r config set maxmemory-clients 0
r client setname control
r client no-evict on
# Make multiple clients consume together roughly 1mb less than maxmemory_clients
set total_client_mem 0
set max_client_mem 0
set rrs {}
for {set j 0} {$j < $client_count} {incr j} {
set rr [redis_client]
lappend rrs $rr
$rr client setname client$j
$rr write [join [list "*2\r\n\$$client_mem\r\n" [string repeat v $client_mem]] ""]
$rr flush
wait_for_condition 200 10 {
[client_field client$j tot-mem] >= $client_mem
} else {
fail "Failed to fill qbuf for test"
}
# In theory all these clients should use the same amount of memory (~1mb). But in practice
# some allocators (libc) can return different allocation sizes for the same malloc argument causing
# some clients to use slightly more memory than others. We find the largest client and make sure
# all clients are roughly the same size (+-1%). Then we can safely set the client eviction limit and
# expect consistent results in the test.
set cmem [client_field client$j tot-mem]
if {$max_client_mem > 0} {
set size_ratio [expr $max_client_mem.0/$cmem.0]
assert_range $size_ratio 0.99 1.01
}
if {$cmem > $max_client_mem} {
set max_client_mem $cmem
}
}
# Make sure all clients are still connected
set connected_clients [llength [lsearch -all [split [string trim [r client list]] "\r\n"] *name=client*]]
assert {$connected_clients == $client_count}
# Set maxmemory-clients to accommodate half our clients (taking into account the control client)
set maxmemory_clients [expr ($max_client_mem * $client_count) / 2 + [client_field control tot-mem]]
r config set maxmemory-clients $maxmemory_clients
# Make sure total used memory is below maxmemory_clients
set total_client_mem [clients_sum tot-mem]
assert {$total_client_mem <= $maxmemory_clients}
# Make sure we have only half of our clients now
set connected_clients [llength [lsearch -all [split [string trim [r client list]] "\r\n"] *name=client*]]
assert {$connected_clients == [expr $client_count / 2]}
# Restore the reply buffer resize to default
r debug replybuffer resizing 1
foreach rr $rrs {$rr close}
} {} {needs:debug}
}
start_server {} {
test "evict clients in right order (large to small)" {
# Note that each size step needs to be at least x2 larger than previous step
# because of how the client-eviction size bucketing works
set sizes [list [kb 128] [mb 1] [mb 3]]
set clients_per_size 3
r client setname control
r client no-evict on
r config set maxmemory-clients 0
r debug replybuffer resizing 0
# Run over all sizes and create some clients using up that size
set total_client_mem 0
set rrs {}
for {set i 0} {$i < [llength $sizes]} {incr i} {
set size [lindex $sizes $i]
for {set j 0} {$j < $clients_per_size} {incr j} {
set rr [redis_client]
lappend rrs $rr
$rr client setname client-$i
$rr write [join [list "*2\r\n\$$size\r\n" [string repeat v $size]] ""]
$rr flush
}
set client_mem [client_field client-$i tot-mem]
# Update our size list based on actual used up size (this is usually
# slightly more than expected because of allocator bins
assert {$client_mem >= $size}
set sizes [lreplace $sizes $i $i $client_mem]
# Account total client memory usage
incr total_mem [expr $clients_per_size * $client_mem]
}
# Make sure all clients are connected
set clients [split [string trim [r client list]] "\r\n"]
for {set i 0} {$i < [llength $sizes]} {incr i} {
assert_equal [llength [lsearch -all $clients "*name=client-$i *"]] $clients_per_size
}
# For each size reduce maxmemory-clients so relevant clients should be evicted
# do this from largest to smallest
foreach size [lreverse $sizes] {
set control_mem [client_field control tot-mem]
set total_mem [expr $total_mem - $clients_per_size * $size]
r config set maxmemory-clients [expr $total_mem + $control_mem]
set clients [split [string trim [r client list]] "\r\n"]
# Verify only relevant clients were evicted
for {set i 0} {$i < [llength $sizes]} {incr i} {
set verify_size [lindex $sizes $i]
set count [llength [lsearch -all $clients "*name=client-$i *"]]
if {$verify_size < $size} {
assert_equal $count $clients_per_size
} else {
assert_equal $count 0
}
}
}
# Restore the reply buffer resize to default
r debug replybuffer resizing 1
foreach rr $rrs {$rr close}
} {} {needs:debug}
}
start_server {} {
foreach type {"client no-evict" "maxmemory-clients disabled"} {
r flushall
r client no-evict on
r config set maxmemory-clients 0
test "client total memory grows during $type" {
r setrange k [mb 1] v
set rr [redis_client]
$rr client setname test_client
if {$type eq "client no-evict"} {
$rr client no-evict on
r config set maxmemory-clients 1
}
$rr deferred 1
# Fill output buffer in loop without reading it and make sure
# the tot-mem of client has increased (OS buffers didn't swallow it)
# and eviction not occurring.
while {true} {
$rr get k
$rr flush
after 10
if {[client_field test_client tot-mem] > [mb 10]} {
break
}
}
# Trigger the client eviction, by flipping the no-evict flag to off
if {$type eq "client no-evict"} {
$rr client no-evict off
} else {
r config set maxmemory-clients 1
}
# wait for the client to be disconnected
wait_for_condition 5000 50 {
![client_exists test_client]
} else {
puts [r client list]
fail "client was not disconnected"
}
$rr close
}
}
}
} ;# tags