redict/tests/unit/scan.tcl
judeng 07ed0eafa9
improve performance for scan command when matching pattern or data type (#12209)
Optimized the performance of the SCAN command in a few ways:
1. Move the key filtering (by MATCH pattern) in the scan callback,
  so as to avoid collecting them for later filtering.
2. Reduce a many memory allocations and copying (use a reference
  to the original sds, instead of creating an robj, an excessive 2 mallocs
  and one string duplication)
3. Compare TYPE filter directly (as integers), instead of inefficient string
  compare per key.
4. fixed a small bug: when scan zset and hash types, maxiterations uses
  a more accurate number to avoid wrong double maxiterations.

Changes **postponed** for a later version (8.0):
1. Prepare to move the TYPE filtering to the scan callback as well. this was
  put on hold since it has side effects that can be considered a breaking
  change, which is that we will not attempt to do lazy expire (delete) a key
  that was filtered by not matching the TYPE (changing it would mean TYPE filter
  starts behaving the same as MATCH filter already does in that respect). 
2. when the specified key TYPE filter is an unknown type, server will reply a error
  immediately instead of doing a full scan that comes back empty handed. 

Benchmark result:
For different scenarios, we obtained about 30% or more performance improvement.

Co-authored-by: Oran Agra <oran@redislabs.com>
2023-06-27 16:43:46 +03:00

434 lines
12 KiB
Tcl

start_server {tags {"scan network"}} {
test "SCAN basic" {
r flushdb
populate 1000
set cur 0
set keys {}
while 1 {
set res [r scan $cur]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
}
set keys [lsort -unique $keys]
assert_equal 1000 [llength $keys]
}
test "SCAN COUNT" {
r flushdb
populate 1000
set cur 0
set keys {}
while 1 {
set res [r scan $cur count 5]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
}
set keys [lsort -unique $keys]
assert_equal 1000 [llength $keys]
}
test "SCAN MATCH" {
r flushdb
populate 1000
set cur 0
set keys {}
while 1 {
set res [r scan $cur match "key:1??"]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
}
set keys [lsort -unique $keys]
assert_equal 100 [llength $keys]
}
test "SCAN TYPE" {
r flushdb
# populate only creates strings
populate 1000
# Check non-strings are excluded
set cur 0
set keys {}
while 1 {
set res [r scan $cur type "list"]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
}
assert_equal 0 [llength $keys]
# Check strings are included
set cur 0
set keys {}
while 1 {
set res [r scan $cur type "string"]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
}
assert_equal 1000 [llength $keys]
# Check all three args work together
set cur 0
set keys {}
while 1 {
set res [r scan $cur type "string" match "key:*" count 10]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
}
assert_equal 1000 [llength $keys]
}
test "SCAN unknown type" {
r flushdb
# make sure that passive expiration is triggered by the scan
r debug set-active-expire 0
populate 1000
r hset hash f v
r pexpire hash 1
after 2
# TODO: remove this in redis 8.0
set cur 0
set keys {}
while 1 {
set res [r scan $cur type "string1"]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
}
assert_equal 0 [llength $keys]
# make sure that expired key have been removed by scan command
assert_equal 1000 [scan [regexp -inline {keys\=([\d]*)} [r info keyspace]] keys=%d]
# TODO: uncomment in redis 8.0
#assert_error "*unknown type name*" {r scan 0 type "string1"}
# expired key will be no touched by scan command
#assert_equal 1001 [scan [regexp -inline {keys\=([\d]*)} [r info keyspace]] keys=%d]
r debug set-active-expire 1
} {OK} {needs:debug}
test "SCAN with expired keys" {
r flushdb
# make sure that passive expiration is triggered by the scan
r debug set-active-expire 0
populate 1000
r set foo bar
r pexpire foo 1
# add a hash type key
r hset hash f v
r pexpire hash 1
after 2
set cur 0
set keys {}
while 1 {
set res [r scan $cur count 10]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
}
assert_equal 1000 [llength $keys]
# make sure that expired key have been removed by scan command
assert_equal 1000 [scan [regexp -inline {keys\=([\d]*)} [r info keyspace]] keys=%d]
r debug set-active-expire 1
} {OK} {needs:debug}
test "SCAN with expired keys with TYPE filter" {
r flushdb
# make sure that passive expiration is triggered by the scan
r debug set-active-expire 0
populate 1000
r set foo bar
r pexpire foo 1
# add a hash type key
r hset hash f v
r pexpire hash 1
after 2
set cur 0
set keys {}
while 1 {
set res [r scan $cur type "string" count 10]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
}
assert_equal 1000 [llength $keys]
# make sure that expired key have been removed by scan command
assert_equal 1000 [scan [regexp -inline {keys\=([\d]*)} [r info keyspace]] keys=%d]
# TODO: uncomment in redis 8.0
# make sure that only the expired key in the type match will been removed by scan command
#assert_equal 1001 [scan [regexp -inline {keys\=([\d]*)} [r info keyspace]] keys=%d]
r debug set-active-expire 1
} {OK} {needs:debug}
foreach enc {intset listpack hashtable} {
test "SSCAN with encoding $enc" {
# Create the Set
r del set
if {$enc eq {intset}} {
set prefix ""
} else {
set prefix "ele:"
}
set count [expr {$enc eq "hashtable" ? 200 : 100}]
set elements {}
for {set j 0} {$j < $count} {incr j} {
lappend elements ${prefix}${j}
}
r sadd set {*}$elements
# Verify that the encoding matches.
assert_encoding $enc set
# Test SSCAN
set cur 0
set keys {}
while 1 {
set res [r sscan set $cur]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
}
set keys [lsort -unique $keys]
assert_equal $count [llength $keys]
}
}
foreach enc {listpack hashtable} {
test "HSCAN with encoding $enc" {
# Create the Hash
r del hash
if {$enc eq {listpack}} {
set count 30
} else {
set count 1000
}
set elements {}
for {set j 0} {$j < $count} {incr j} {
lappend elements key:$j $j
}
r hmset hash {*}$elements
# Verify that the encoding matches.
assert_encoding $enc hash
# Test HSCAN
set cur 0
set keys {}
while 1 {
set res [r hscan hash $cur]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
}
set keys2 {}
foreach {k v} $keys {
assert {$k eq "key:$v"}
lappend keys2 $k
}
set keys2 [lsort -unique $keys2]
assert_equal $count [llength $keys2]
}
}
foreach enc {listpack skiplist} {
test "ZSCAN with encoding $enc" {
# Create the Sorted Set
r del zset
if {$enc eq {listpack}} {
set count 30
} else {
set count 1000
}
set elements {}
for {set j 0} {$j < $count} {incr j} {
lappend elements $j key:$j
}
r zadd zset {*}$elements
# Verify that the encoding matches.
assert_encoding $enc zset
# Test ZSCAN
set cur 0
set keys {}
while 1 {
set res [r zscan zset $cur]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
}
set keys2 {}
foreach {k v} $keys {
assert {$k eq "key:$v"}
lappend keys2 $k
}
set keys2 [lsort -unique $keys2]
assert_equal $count [llength $keys2]
}
}
test "SCAN guarantees check under write load" {
r flushdb
populate 100
# We start scanning here, so keys from 0 to 99 should all be
# reported at the end of the iteration.
set keys {}
while 1 {
set res [r scan $cur]
set cur [lindex $res 0]
set k [lindex $res 1]
lappend keys {*}$k
if {$cur == 0} break
# Write 10 random keys at every SCAN iteration.
for {set j 0} {$j < 10} {incr j} {
r set addedkey:[randomInt 1000] foo
}
}
set keys2 {}
foreach k $keys {
if {[string length $k] > 6} continue
lappend keys2 $k
}
set keys2 [lsort -unique $keys2]
assert_equal 100 [llength $keys2]
}
test "SSCAN with integer encoded object (issue #1345)" {
set objects {1 a}
r del set
r sadd set {*}$objects
set res [r sscan set 0 MATCH *a* COUNT 100]
assert_equal [lsort -unique [lindex $res 1]] {a}
set res [r sscan set 0 MATCH *1* COUNT 100]
assert_equal [lsort -unique [lindex $res 1]] {1}
}
test "SSCAN with PATTERN" {
r del mykey
r sadd mykey foo fab fiz foobar 1 2 3 4
set res [r sscan mykey 0 MATCH foo* COUNT 10000]
lsort -unique [lindex $res 1]
} {foo foobar}
test "HSCAN with PATTERN" {
r del mykey
r hmset mykey foo 1 fab 2 fiz 3 foobar 10 1 a 2 b 3 c 4 d
set res [r hscan mykey 0 MATCH foo* COUNT 10000]
lsort -unique [lindex $res 1]
} {1 10 foo foobar}
test "ZSCAN with PATTERN" {
r del mykey
r zadd mykey 1 foo 2 fab 3 fiz 10 foobar
set res [r zscan mykey 0 MATCH foo* COUNT 10000]
lsort -unique [lindex $res 1]
}
test "ZSCAN scores: regression test for issue #2175" {
r del mykey
for {set j 0} {$j < 500} {incr j} {
r zadd mykey 9.8813129168249309e-323 $j
}
set res [lindex [r zscan mykey 0] 1]
set first_score [lindex $res 1]
assert {$first_score != 0}
}
test "SCAN regression test for issue #4906" {
for {set k 0} {$k < 100} {incr k} {
r del set
r sadd set x; # Make sure it's not intset encoded
set toremove {}
unset -nocomplain found
array set found {}
# Populate the set
set numele [expr {101+[randomInt 1000]}]
for {set j 0} {$j < $numele} {incr j} {
r sadd set $j
if {$j >= 100} {
lappend toremove $j
}
}
# Start scanning
set cursor 0
set iteration 0
set del_iteration [randomInt 10]
while {!($cursor == 0 && $iteration != 0)} {
lassign [r sscan set $cursor] cursor items
# Mark found items. We expect to find from 0 to 99 at the end
# since those elements will never be removed during the scanning.
foreach i $items {
set found($i) 1
}
incr iteration
# At some point remove most of the items to trigger the
# rehashing to a smaller hash table.
if {$iteration == $del_iteration} {
r srem set {*}$toremove
}
}
# Verify that SSCAN reported everything from 0 to 99
for {set j 0} {$j < 100} {incr j} {
if {![info exists found($j)]} {
fail "SSCAN element missing $j"
}
}
}
}
}