redict/tests/unit/memefficiency.tcl
Oran Agra 485425cec7 Defrag big lists in portions to avoid latency and freeze
When active defrag kicks in and finds a big list, it will create a bookmark to
a node so that it is able to resume iteration from that node later.

The quicklist manages that bookmark, and updates it in case that node is deleted.

This will increase memory usage only on lists of over 1000 (see
active-defrag-max-scan-fields) quicklist nodes (1000 ziplists, not 1000 items)
by 16 bytes.

In 32 bit build, this change reduces the maximum effective config of
list-compress-depth and list-max-ziplist-size (from 32767 to 8191)
2020-02-18 17:22:32 +02:00

306 lines
12 KiB
Tcl

proc test_memory_efficiency {range} {
r flushall
set rd [redis_deferring_client]
set base_mem [s used_memory]
set written 0
for {set j 0} {$j < 10000} {incr j} {
set key key:$j
set val [string repeat A [expr {int(rand()*$range)}]]
$rd set $key $val
incr written [string length $key]
incr written [string length $val]
incr written 2 ;# A separator is the minimum to store key-value data.
}
for {set j 0} {$j < 10000} {incr j} {
$rd read ; # Discard replies
}
set current_mem [s used_memory]
set used [expr {$current_mem-$base_mem}]
set efficiency [expr {double($written)/$used}]
return $efficiency
}
start_server {tags {"memefficiency"}} {
foreach {size_range expected_min_efficiency} {
32 0.15
64 0.25
128 0.35
1024 0.75
16384 0.82
} {
test "Memory efficiency with values in range $size_range" {
set efficiency [test_memory_efficiency $size_range]
assert {$efficiency >= $expected_min_efficiency}
}
}
}
start_server {tags {"defrag"}} {
if {[string match {*jemalloc*} [s mem_allocator]]} {
test "Active defrag" {
r config set activedefrag no
r config set active-defrag-threshold-lower 5
r config set active-defrag-cycle-min 65
r config set active-defrag-cycle-max 75
r config set active-defrag-ignore-bytes 2mb
r config set maxmemory 100mb
r config set maxmemory-policy allkeys-lru
r debug populate 700000 asdf 150
r debug populate 170000 asdf 300
r ping ;# trigger eviction following the previous population
after 120 ;# serverCron only updates the info once in 100ms
set frag [s allocator_frag_ratio]
if {$::verbose} {
puts "frag $frag"
}
assert {$frag >= 1.4}
catch {r config set activedefrag yes} e
if {![string match {DISABLED*} $e]} {
# Wait for the active defrag to start working (decision once a
# second).
wait_for_condition 50 100 {
[s active_defrag_running] ne 0
} else {
fail "defrag not started."
}
# Wait for the active defrag to stop working.
wait_for_condition 150 100 {
[s active_defrag_running] eq 0
} else {
after 120 ;# serverCron only updates the info once in 100ms
puts [r info memory]
puts [r memory malloc-stats]
fail "defrag didn't stop."
}
# Test the the fragmentation is lower.
after 120 ;# serverCron only updates the info once in 100ms
set frag [s allocator_frag_ratio]
if {$::verbose} {
puts "frag $frag"
}
assert {$frag < 1.1}
} else {
set _ ""
}
} {}
test "Active defrag big keys" {
r flushdb
r config resetstat
r config set save "" ;# prevent bgsave from interfereing with save below
r config set activedefrag no
r config set active-defrag-max-scan-fields 1000
r config set active-defrag-threshold-lower 5
r config set active-defrag-cycle-min 65
r config set active-defrag-cycle-max 75
r config set active-defrag-ignore-bytes 2mb
r config set maxmemory 0
r config set list-max-ziplist-size 5 ;# list of 10k items will have 2000 quicklist nodes
r config set stream-node-max-entries 5
r hmset hash h1 v1 h2 v2 h3 v3
r lpush list a b c d
r zadd zset 0 a 1 b 2 c 3 d
r sadd set a b c d
r xadd stream * item 1 value a
r xadd stream * item 2 value b
r xgroup create stream mygroup 0
r xreadgroup GROUP mygroup Alice COUNT 1 STREAMS stream >
# create big keys with 10k items
set rd [redis_deferring_client]
for {set j 0} {$j < 10000} {incr j} {
$rd hset bighash $j [concat "asdfasdfasdf" $j]
$rd lpush biglist [concat "asdfasdfasdf" $j]
$rd zadd bigzset $j [concat "asdfasdfasdf" $j]
$rd sadd bigset [concat "asdfasdfasdf" $j]
$rd xadd bigstream * item 1 value a
}
for {set j 0} {$j < 50000} {incr j} {
$rd read ; # Discard replies
}
set expected_frag 1.7
if {$::accurate} {
# scale the hash to 1m fields in order to have a measurable the latency
for {set j 10000} {$j < 1000000} {incr j} {
$rd hset bighash $j [concat "asdfasdfasdf" $j]
}
for {set j 10000} {$j < 1000000} {incr j} {
$rd read ; # Discard replies
}
# creating that big hash, increased used_memory, so the relative frag goes down
set expected_frag 1.3
}
# add a mass of string keys
for {set j 0} {$j < 500000} {incr j} {
$rd setrange $j 150 a
}
for {set j 0} {$j < 500000} {incr j} {
$rd read ; # Discard replies
}
assert {[r dbsize] == 500010}
# create some fragmentation
for {set j 0} {$j < 500000} {incr j 2} {
$rd del $j
}
for {set j 0} {$j < 500000} {incr j 2} {
$rd read ; # Discard replies
}
assert {[r dbsize] == 250010}
# start defrag
after 120 ;# serverCron only updates the info once in 100ms
set frag [s allocator_frag_ratio]
if {$::verbose} {
puts "frag $frag"
}
assert {$frag >= $expected_frag}
r config set latency-monitor-threshold 5
r latency reset
set digest [r debug digest]
catch {r config set activedefrag yes} e
if {![string match {DISABLED*} $e]} {
# wait for the active defrag to start working (decision once a second)
wait_for_condition 50 100 {
[s active_defrag_running] ne 0
} else {
fail "defrag not started."
}
# wait for the active defrag to stop working
wait_for_condition 500 100 {
[s active_defrag_running] eq 0
} else {
after 120 ;# serverCron only updates the info once in 100ms
puts [r info memory]
puts [r memory malloc-stats]
fail "defrag didn't stop."
}
# test the the fragmentation is lower
after 120 ;# serverCron only updates the info once in 100ms
set frag [s allocator_frag_ratio]
set max_latency 0
foreach event [r latency latest] {
lassign $event eventname time latency max
if {$eventname == "active-defrag-cycle"} {
set max_latency $max
}
}
if {$::verbose} {
puts "frag $frag"
puts "max latency $max_latency"
puts [r latency latest]
puts [r latency history active-defrag-cycle]
}
assert {$frag < 1.1}
# due to high fragmentation, 10hz, and active-defrag-cycle-max set to 75,
# we expect max latency to be not much higher than 75ms
assert {$max_latency <= 120}
}
# verify the data isn't corrupted or changed
set newdigest [r debug digest]
assert {$digest eq $newdigest}
r save ;# saving an rdb iterates over all the data / pointers
} {OK}
test "Active defrag big list" {
r flushdb
r config resetstat
r config set save "" ;# prevent bgsave from interfereing with save below
r config set hz 100
r config set activedefrag no
r config set active-defrag-max-scan-fields 1000
r config set active-defrag-threshold-lower 5
r config set active-defrag-cycle-min 65
r config set active-defrag-cycle-max 75
r config set active-defrag-ignore-bytes 2mb
r config set maxmemory 0
r config set list-max-ziplist-size 5 ;# list of 500k items will have 100k quicklist nodes
# create big keys with 10k items
set rd [redis_deferring_client]
set expected_frag 1.7
# add a mass of list nodes to two lists (allocations are interlaced)
set val [string repeat A 100] ;# 5 items of 100 bytes puts us in the 640 bytes bin, which has 32 regs, so high potential for fragmentation
for {set j 0} {$j < 500000} {incr j} {
$rd lpush biglist1 $val
$rd lpush biglist2 $val
}
for {set j 0} {$j < 500000} {incr j} {
$rd read ; # Discard replies
$rd read ; # Discard replies
}
# create some fragmentation
r del biglist2
# start defrag
after 120 ;# serverCron only updates the info once in 100ms
set frag [s allocator_frag_ratio]
if {$::verbose} {
puts "frag $frag"
}
assert {$frag >= $expected_frag}
r config set latency-monitor-threshold 5
r latency reset
set digest [r debug digest]
catch {r config set activedefrag yes} e
if {![string match {DISABLED*} $e]} {
# wait for the active defrag to start working (decision once a second)
wait_for_condition 50 100 {
[s active_defrag_running] ne 0
} else {
fail "defrag not started."
}
# wait for the active defrag to stop working
wait_for_condition 500 100 {
[s active_defrag_running] eq 0
} else {
after 120 ;# serverCron only updates the info once in 100ms
puts [r info memory]
puts [r info stats]
puts [r memory malloc-stats]
fail "defrag didn't stop."
}
# test the the fragmentation is lower
after 120 ;# serverCron only updates the info once in 100ms
set frag [s allocator_frag_ratio]
set max_latency 0
foreach event [r latency latest] {
lassign $event eventname time latency max
if {$eventname == "active-defrag-cycle"} {
set max_latency $max
}
}
if {$::verbose} {
puts "frag $frag"
puts "max latency $max_latency"
puts [r latency latest]
puts [r latency history active-defrag-cycle]
}
assert {$frag < 1.1}
# due to high fragmentation, 100hz, and active-defrag-cycle-max set to 75,
# we expect max latency to be not much higher than 7.5ms
assert {$max_latency <= 12}
}
# verify the data isn't corrupted or changed
set newdigest [r debug digest]
assert {$digest eq $newdigest}
r save ;# saving an rdb iterates over all the data / pointers
r del biglist1 ;# coverage for quicklistBookmarksClear
} {1}
}
}