1.1 milliard taksi safari: 108 yadroli ClickHouse klasteri

Maqolaning tarjimasi kurs talabalari uchun maxsus tayyorlangan Ma'lumotlar muhandisi.

1.1 milliard taksi safari: 108 yadroli ClickHouse klasteri

ClickHouse ochiq manbali ustunli ma'lumotlar bazasi. Bu har kuni o'nlab milliardlab yangi yozuvlar kiritilsa ham, yuzlab tahlilchilar tezda batafsil ma'lumotlarni so'rashlari mumkin bo'lgan ajoyib muhit. Bunday tizimni qo'llab-quvvatlash uchun infratuzilma xarajatlari yiliga 100 10 dollarni tashkil qilishi mumkin va foydalanishga bog'liq bo'lishi mumkin. Bir vaqtlar Yandex Metrics-dan ClickHouse o'rnatilishi XNUMX trillion yozuvni o'z ichiga olgan. Yandexdan tashqari ClickHouse ham Bloomberg va Cloudflare bilan muvaffaqiyat qozondi.

Ikki yil oldin men o'tkazdim qiyosiy tahlil bir mashina yordamida ma'lumotlar bazalari, va u aylandi eng tez Men ko'rgan bepul ma'lumotlar bazasi dasturi. O'shandan beri ishlab chiquvchilar Kafka, HDFS va ZStandard siqishni qo'llab-quvvatlash kabi xususiyatlarni qo'shishni davom ettirdilar. O'tgan yili ular kaskadli siqish usullarini qo'llab-quvvatlashni qo'shdilar va deltadan-deltadan kodlash imkoniyati paydo bo‘ldi. Vaqt seriyali ma'lumotlarini siqishda o'lchov qiymatlarini delta kodlash yordamida yaxshi siqish mumkin, ammo hisoblagichlar uchun uchburchak kodlashdan foydalanish yaxshi bo'ladi. Yaxshi siqish ClickHouse ishlashining kalitiga aylandi.

ClickHouse uchinchi tomon kutubxonalari bundan mustasno 170 ming satr C++ kodidan iborat boʻlib, eng kichik taqsimlangan maʼlumotlar bazasi kod bazalaridan biridir. Taqqoslash uchun, SQLite tarqatishni qo'llab-quvvatlamaydi va 235 ming satr C kodidan iborat.Ushbu yozilishgacha ClickHouse-ga 207 muhandis o'z hissasini qo'shgan va so'nggi paytlarda majburiyatlar intensivligi ortib bormoqda.

2017 yil mart oyida ClickHouse o'z faoliyatini boshladi o'zgarishlar jurnali rivojlanishni kuzatishning oson usuli sifatida. Ular, shuningdek, monolit hujjat faylini Markdown-ga asoslangan fayl ierarxiyasiga bo'lishdi. Muammolar va xususiyatlar GitHub orqali kuzatib boriladi va umuman olganda, dasturiy ta'minot so'nggi bir necha yil ichida ancha qulayroq bo'ldi.

Ushbu maqolada men 2 yadroli protsessorlar va NVMe xotirasidan foydalangan holda AWS EC36 da ClickHouse klasterining ishlashini ko'rib chiqmoqchiman.

YANGILANISH: Ushbu postni dastlab e'lon qilgandan bir hafta o'tgach, men testni yaxshilangan konfiguratsiya bilan qayta o'tkazdim va ancha yaxshi natijalarga erishdim. Ushbu o'zgarishlarni aks ettirish uchun ushbu post yangilandi.

AWS EC2 klasterini ishga tushirish

Men ushbu post uchun uchta c5d.9xlarge EC2 nusxasidan foydalanaman. Ularning har birida 36 ta virtual protsessor, 72 Gb tezkor xotira, 900 Gb NVMe SSD xotirasi mavjud va 10 Gigabit tarmoqni qo‘llab-quvvatlaydi. Eu-west-1,962 mintaqasida talab bo'yicha ishlayotganda ularning har biri soatiga 1 dollar turadi. Men operatsion tizim sifatida Ubuntu Server 16.04 LTS dan foydalanaman.

Xavfsizlik devori shunday tuzilganki, har bir mashina bir-biri bilan cheklovsiz muloqot qila oladi va faqat mening IPv4 manzilim klasterda SSH tomonidan oq ro‘yxatga kiritilgan.

NVMe drayveri ishlashga tayyor holatda

ClickHouse ishlashi uchun men har bir serverda NVMe diskida EXT4 formatida fayl tizimini yarataman.

$ sudo mkfs -t ext4 /dev/nvme1n1
$ sudo mkdir /ch
$ sudo mount /dev/nvme1n1 /ch

Har bir narsa sozlangandan so'ng, siz o'rnatish nuqtasini va har bir tizimda mavjud bo'lgan 783 GB bo'sh joyni ko'rishingiz mumkin.

$ lsblk

NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
loop0         7:0    0  87.9M  1 loop /snap/core/5742
loop1         7:1    0  16.5M  1 loop /snap/amazon-ssm-agent/784
nvme0n1     259:1    0     8G  0 disk
└─nvme0n1p1 259:2    0     8G  0 part /
nvme1n1     259:0    0 838.2G  0 disk /ch

$ df -h

Filesystem      Size  Used Avail Use% Mounted on
udev             35G     0   35G   0% /dev
tmpfs           6.9G  8.8M  6.9G   1% /run
/dev/nvme0n1p1  7.7G  967M  6.8G  13% /
tmpfs            35G     0   35G   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs            35G     0   35G   0% /sys/fs/cgroup
/dev/loop0       88M   88M     0 100% /snap/core/5742
/dev/loop1       17M   17M     0 100% /snap/amazon-ssm-agent/784
tmpfs           6.9G     0  6.9G   0% /run/user/1000
/dev/nvme1n1    825G   73M  783G   1% /ch

Ushbu testda men foydalanadigan ma'lumotlar to'plami men olti yil davomida Nyu-York shahrida 1.1 milliard taksi safari natijasida yaratilgan ma'lumotlar to'plamidir. Blogda Redshiftda bir milliard taksi safari ushbu ma'lumotlar to'plamini qanday to'plaganim haqida batafsil ma'lumot. Ular AWS S3 da saqlanadi, shuning uchun men kirish va maxfiy kalitlarim bilan AWS CLI ni sozlayman.

$ sudo apt update
$ sudo apt install awscli
$ aws configure

Fayllar standart sozlamalardan tezroq yuklab olinishi uchun mijozning bir vaqtda soʻrovi chegarasini 100 ga oʻrnataman.

$ aws configure set 
    default.s3.max_concurrent_requests 
    100

Men AWS S3-dan taksi safarlari ma'lumotlar to'plamini yuklab olaman va uni birinchi serverdagi NVMe diskida saqlayman. Bu maʼlumotlar toʻplami GZIP-siqilgan CSV formatida ~104GB.

$ sudo mkdir -p /ch/csv
$ sudo chown -R ubuntu /ch/csv
$ aws s3 sync s3://<bucket>/csv /ch/csv

ClickHouse o'rnatish

Men Java 8 uchun OpenJDK distributivini o'rnataman, chunki u Apache ZooKeeper-ni ishga tushirish uchun talab qilinadi, bu ClickHouse-ni barcha uchta mashinada taqsimlangan o'rnatish uchun zarurdir.

$ sudo apt update
$ sudo apt install 
    openjdk-8-jre 
    openjdk-8-jdk-headless

Keyin muhit o'zgaruvchisini o'rnatdim JAVA_HOME.

$ sudo vi /etc/profile
 
export JAVA_HOME=/usr
 
$ source /etc/profile

Keyin Ubuntu paketlarini boshqarish tizimidan uchta mashinada ClickHouse 18.16.1, glances va ZooKeeperni o'rnatish uchun foydalanaman.

$ sudo apt-key adv 
    --keyserver hkp://keyserver.ubuntu.com:80 
    --recv E0C56BD4
$ echo "deb http://repo.yandex.ru/clickhouse/deb/stable/ main/" | 
    sudo tee /etc/apt/sources.list.d/clickhouse.list
$ sudo apt-get update

$ sudo apt install 
    clickhouse-client 
    clickhouse-server 
    glances 
    zookeeperd

Men ClickHouse uchun katalog yarataman va barcha uchta serverda konfiguratsiyani bekor qilaman.

$ sudo mkdir /ch/clickhouse
$ sudo chown -R clickhouse /ch/clickhouse

$ sudo mkdir -p /etc/clickhouse-server/conf.d
$ sudo vi /etc/clickhouse-server/conf.d/taxis.conf

Bular men foydalanadigan konfiguratsiyani bekor qilishdir.

<?xml version="1.0"?>
<yandex>
    <listen_host>0.0.0.0</listen_host>
    <path>/ch/clickhouse/</path>

 <remote_servers>
        <perftest_3shards>
            <shard>
                <replica>
                    <host>172.30.2.192</host>
                    <port>9000</port>
                 </replica>
            </shard>
            <shard>
                 <replica>
                    <host>172.30.2.162</host>
                    <port>9000</port>
                 </replica>
            </shard>
            <shard>
                 <replica>
                    <host>172.30.2.36</host>
                    <port>9000</port>
                 </replica>
            </shard>
        </perftest_3shards>
    </remote_servers>

  <zookeeper-servers>
        <node>
            <host>172.30.2.192</host>
            <port>2181</port>
        </node>
        <node>
            <host>172.30.2.162</host>
            <port>2181</port>
        </node>
        <node>
            <host>172.30.2.36</host>
            <port>2181</port>
        </node>
    </zookeeper-servers>

 <macros>
        <shard>03</shard>
        <replica>01</replica>
    </macros>
</yandex>

Keyin ZooKeeper va ClickHouse serverini uchta mashinada ishga tushiraman.

$ sudo /etc/init.d/zookeeper start
$ sudo service clickhouse-server start

ClickHouse-ga ma'lumotlar yuklanmoqda

Birinchi serverda men sayohat jadvalini yarataman (trips), bu log dvigateli yordamida taksi safarlari ma'lumotlar to'plamini saqlaydi.

$ clickhouse-client --host=0.0.0.0
 
CREATE TABLE trips (
    trip_id                 UInt32,
    vendor_id               String,

    pickup_datetime         DateTime,
    dropoff_datetime        Nullable(DateTime),

    store_and_fwd_flag      Nullable(FixedString(1)),
    rate_code_id            Nullable(UInt8),
    pickup_longitude        Nullable(Float64),
    pickup_latitude         Nullable(Float64),
    dropoff_longitude       Nullable(Float64),
    dropoff_latitude        Nullable(Float64),
    passenger_count         Nullable(UInt8),
    trip_distance           Nullable(Float64),
    fare_amount             Nullable(Float32),
    extra                   Nullable(Float32),
    mta_tax                 Nullable(Float32),
    tip_amount              Nullable(Float32),
    tolls_amount            Nullable(Float32),
    ehail_fee               Nullable(Float32),
    improvement_surcharge   Nullable(Float32),
    total_amount            Nullable(Float32),
    payment_type            Nullable(String),
    trip_type               Nullable(UInt8),
    pickup                  Nullable(String),
    dropoff                 Nullable(String),

    cab_type                Nullable(String),

    precipitation           Nullable(Int8),
    snow_depth              Nullable(Int8),
    snowfall                Nullable(Int8),
    max_temperature         Nullable(Int8),
    min_temperature         Nullable(Int8),
    average_wind_speed      Nullable(Int8),

    pickup_nyct2010_gid     Nullable(Int8),
    pickup_ctlabel          Nullable(String),
    pickup_borocode         Nullable(Int8),
    pickup_boroname         Nullable(String),
    pickup_ct2010           Nullable(String),
    pickup_boroct2010       Nullable(String),
    pickup_cdeligibil       Nullable(FixedString(1)),
    pickup_ntacode          Nullable(String),
    pickup_ntaname          Nullable(String),
    pickup_puma             Nullable(String),

    dropoff_nyct2010_gid    Nullable(UInt8),
    dropoff_ctlabel         Nullable(String),
    dropoff_borocode        Nullable(UInt8),
    dropoff_boroname        Nullable(String),
    dropoff_ct2010          Nullable(String),
    dropoff_boroct2010      Nullable(String),
    dropoff_cdeligibil      Nullable(String),
    dropoff_ntacode         Nullable(String),
    dropoff_ntaname         Nullable(String),
    dropoff_puma            Nullable(String)
) ENGINE = Log;

Keyin men har bir CSV faylini chiqarib, sayohat jadvaliga yuklayman (trips). Quyidagi 55 daqiqa 10 soniyada bajarildi. Ushbu operatsiyadan so'ng ma'lumotlar katalogining hajmi 134 GB edi.

$ time (for FILENAME in /ch/csv/trips_x*.csv.gz; do
            echo $FILENAME
            gunzip -c $FILENAME | 
                clickhouse-client 
                    --host=0.0.0.0 
                    --query="INSERT INTO trips FORMAT CSV"
        done)

Import tezligi soniyasiga 155 MB siqilmagan CSV kontentini tashkil etdi. Menimcha, bu GZIP dekompressiyasidagi muammo tufayli bo'lgan. Xargs yordamida barcha gzip fayllarni parallel ravishda ochish va keyin ochilgan ma'lumotlarni yuklash tezroq bo'lishi mumkin edi. Quyida CSV import jarayonida xabar qilingan narsalarning tavsifi keltirilgan.

$ sudo glances

ip-172-30-2-200 (Ubuntu 16.04 64bit / Linux 4.4.0-1072-aws)                                                                                                 Uptime: 0:11:42
CPU       8.2%  nice:     0.0%                           LOAD    36-core                           MEM      9.8%  active:    5.20G                           SWAP      0.0%
user:     6.0%  irq:      0.0%                           1 min:    2.24                            total:  68.7G  inactive:  61.0G                           total:       0
system:   0.9%  iowait:   1.3%                           5 min:    1.83                            used:   6.71G  buffers:   66.4M                           used:        0
idle:    91.8%  steal:    0.0%                           15 min:   1.01                            free:   62.0G  cached:    61.6G                           free:        0

NETWORK     Rx/s   Tx/s   TASKS 370 (507 thr), 2 run, 368 slp, 0 oth sorted automatically by cpu_percent, flat view
ens5        136b    2Kb
lo         343Mb  343Mb     CPU%  MEM%  VIRT   RES   PID USER        NI S    TIME+ IOR/s IOW/s Command
                           100.4   1.5 1.65G 1.06G  9909 ubuntu       0 S  1:01.33     0     0 clickhouse-client --host=0.0.0.0 --query=INSERT INTO trips FORMAT CSV
DISK I/O     R/s    W/s     85.1   0.0 4.65M  708K  9908 ubuntu       0 R  0:50.60   32M     0 gzip -d -c /ch/csv/trips_xac.csv.gz
loop0          0      0     54.9   5.1 8.14G 3.49G  8091 clickhous    0 S  1:44.23     0   45M /usr/bin/clickhouse-server --config=/etc/clickhouse-server/config.xml
loop1          0      0      4.5   0.0     0     0   319 root         0 S  0:07.50    1K     0 kworker/u72:2
nvme0n1        0     3K      2.3   0.0 91.1M 28.9M  9912 root         0 R  0:01.56     0     0 /usr/bin/python3 /usr/bin/glances
nvme0n1p1      0     3K      0.3   0.0     0     0   960 root       -20 S  0:00.10     0     0 kworker/28:1H
nvme1n1    32.1M   495M      0.3   0.0     0     0  1058 root       -20 S  0:00.90     0     0 kworker/23:1H

Davom etishdan oldin asl CSV fayllarini o‘chirib, NVMe diskida joy bo‘shatib qo‘yaman.

$ sudo rm -fr /ch/csv

Ustun shakliga aylantirish

Log ClickHouse mexanizmi ma'lumotlarni qatorga yo'naltirilgan formatda saqlaydi. Ma'lumotlarni tezroq so'rash uchun MergeTree mexanizmi yordamida uni ustunli formatga aylantiraman.

$ clickhouse-client --host=0.0.0.0

Quyidagi 34 daqiqa 50 soniyada bajarildi. Ushbu operatsiyadan so'ng, ma'lumotlar katalogining hajmi 237 GB edi.

CREATE TABLE trips_mergetree
    ENGINE = MergeTree(pickup_date, pickup_datetime, 8192)
    AS SELECT
        trip_id,
        CAST(vendor_id AS Enum8('1' = 1,
                                '2' = 2,
                                'CMT' = 3,
                                'VTS' = 4,
                                'DDS' = 5,
                                'B02512' = 10,
                                'B02598' = 11,
                                'B02617' = 12,
                                'B02682' = 13,
                                'B02764' = 14)) AS vendor_id,
        toDate(pickup_datetime)                 AS pickup_date,
        ifNull(pickup_datetime, toDateTime(0))  AS pickup_datetime,
        toDate(dropoff_datetime)                AS dropoff_date,
        ifNull(dropoff_datetime, toDateTime(0)) AS dropoff_datetime,
        assumeNotNull(store_and_fwd_flag)       AS store_and_fwd_flag,
        assumeNotNull(rate_code_id)             AS rate_code_id,

        assumeNotNull(pickup_longitude)         AS pickup_longitude,
        assumeNotNull(pickup_latitude)          AS pickup_latitude,
        assumeNotNull(dropoff_longitude)        AS dropoff_longitude,
        assumeNotNull(dropoff_latitude)         AS dropoff_latitude,
        assumeNotNull(passenger_count)          AS passenger_count,
        assumeNotNull(trip_distance)            AS trip_distance,
        assumeNotNull(fare_amount)              AS fare_amount,
        assumeNotNull(extra)                    AS extra,
        assumeNotNull(mta_tax)                  AS mta_tax,
        assumeNotNull(tip_amount)               AS tip_amount,
        assumeNotNull(tolls_amount)             AS tolls_amount,
        assumeNotNull(ehail_fee)                AS ehail_fee,
        assumeNotNull(improvement_surcharge)    AS improvement_surcharge,
        assumeNotNull(total_amount)             AS total_amount,
        assumeNotNull(payment_type)             AS payment_type_,
        assumeNotNull(trip_type)                AS trip_type,

        pickup AS pickup,
        pickup AS dropoff,

        CAST(assumeNotNull(cab_type)
            AS Enum8('yellow' = 1, 'green' = 2))
                                AS cab_type,

        precipitation           AS precipitation,
        snow_depth              AS snow_depth,
        snowfall                AS snowfall,
        max_temperature         AS max_temperature,
        min_temperature         AS min_temperature,
        average_wind_speed      AS average_wind_speed,

        pickup_nyct2010_gid     AS pickup_nyct2010_gid,
        pickup_ctlabel          AS pickup_ctlabel,
        pickup_borocode         AS pickup_borocode,
        pickup_boroname         AS pickup_boroname,
        pickup_ct2010           AS pickup_ct2010,
        pickup_boroct2010       AS pickup_boroct2010,
        pickup_cdeligibil       AS pickup_cdeligibil,
        pickup_ntacode          AS pickup_ntacode,
        pickup_ntaname          AS pickup_ntaname,
        pickup_puma             AS pickup_puma,

        dropoff_nyct2010_gid    AS dropoff_nyct2010_gid,
        dropoff_ctlabel         AS dropoff_ctlabel,
        dropoff_borocode        AS dropoff_borocode,
        dropoff_boroname        AS dropoff_boroname,
        dropoff_ct2010          AS dropoff_ct2010,
        dropoff_boroct2010      AS dropoff_boroct2010,
        dropoff_cdeligibil      AS dropoff_cdeligibil,
        dropoff_ntacode         AS dropoff_ntacode,
        dropoff_ntaname         AS dropoff_ntaname,
        dropoff_puma            AS dropoff_puma
    FROM trips;

Operatsiya paytida ko'rish chiqishi quyidagicha ko'rinadi:

ip-172-30-2-200 (Ubuntu 16.04 64bit / Linux 4.4.0-1072-aws)                                                                                                 Uptime: 1:06:09
CPU      10.3%  nice:     0.0%                           LOAD    36-core                           MEM     16.1%  active:    13.3G                           SWAP      0.0%
user:     7.9%  irq:      0.0%                           1 min:    1.87                            total:  68.7G  inactive:  52.8G                           total:       0
system:   1.6%  iowait:   0.8%                           5 min:    1.76                            used:   11.1G  buffers:   71.8M                           used:        0
idle:    89.7%  steal:    0.0%                           15 min:   1.95                            free:   57.6G  cached:    57.2G                           free:        0

NETWORK     Rx/s   Tx/s   TASKS 367 (523 thr), 1 run, 366 slp, 0 oth sorted automatically by cpu_percent, flat view
ens5         1Kb    8Kb
lo           2Kb    2Kb     CPU%  MEM%  VIRT   RES   PID USER        NI S    TIME+ IOR/s IOW/s Command
                           241.9  12.8 20.7G 8.78G  8091 clickhous    0 S 30:36.73   34M  125M /usr/bin/clickhouse-server --config=/etc/clickhouse-server/config.xml
DISK I/O     R/s    W/s      2.6   0.0 90.4M 28.3M  9948 root         0 R  1:18.53     0     0 /usr/bin/python3 /usr/bin/glances
loop0          0      0      1.3   0.0     0     0   203 root         0 S  0:09.82     0     0 kswapd0
loop1          0      0      0.3   0.1  315M 61.3M 15701 ubuntu       0 S  0:00.40     0     0 clickhouse-client --host=0.0.0.0
nvme0n1        0     3K      0.3   0.0     0     0     7 root         0 S  0:00.83     0     0 rcu_sched
nvme0n1p1      0     3K      0.0   0.0     0     0   142 root         0 S  0:00.22     0     0 migration/27
nvme1n1    25.8M   330M      0.0   0.0 59.7M 1.79M  2764 ubuntu       0 S  0:00.00     0     0 (sd-pam)

Oxirgi testda bir nechta ustunlar aylantirildi va qayta hisoblab chiqildi. Men ushbu funktsiyalarning ba'zilari endi ushbu ma'lumotlar to'plamida kutilganidek ishlamasligini aniqladim. Ushbu muammoni hal qilish uchun men nomaqbul funktsiyalarni olib tashladim va ma'lumotlarni ko'proq donador turlarga aylantirmasdan yukladim.

Klaster bo'yicha ma'lumotlarni taqsimlash

Men ma'lumotlarni barcha uchta klaster tugunlari bo'ylab tarqataman. Boshlash uchun quyida men uchta mashinada jadval yarataman.

$ clickhouse-client --host=0.0.0.0

CREATE TABLE trips_mergetree_third (
    trip_id                 UInt32,
    vendor_id               String,
    pickup_date             Date,
    pickup_datetime         DateTime,
    dropoff_date            Date,
    dropoff_datetime        Nullable(DateTime),
    store_and_fwd_flag      Nullable(FixedString(1)),
    rate_code_id            Nullable(UInt8),
    pickup_longitude        Nullable(Float64),
    pickup_latitude         Nullable(Float64),
    dropoff_longitude       Nullable(Float64),
    dropoff_latitude        Nullable(Float64),
    passenger_count         Nullable(UInt8),
    trip_distance           Nullable(Float64),
    fare_amount             Nullable(Float32),
    extra                   Nullable(Float32),
    mta_tax                 Nullable(Float32),
    tip_amount              Nullable(Float32),
    tolls_amount            Nullable(Float32),
    ehail_fee               Nullable(Float32),
    improvement_surcharge   Nullable(Float32),
    total_amount            Nullable(Float32),
    payment_type            Nullable(String),
    trip_type               Nullable(UInt8),
    pickup                  Nullable(String),
    dropoff                 Nullable(String),

    cab_type                Nullable(String),

    precipitation           Nullable(Int8),
    snow_depth              Nullable(Int8),
    snowfall                Nullable(Int8),
    max_temperature         Nullable(Int8),
    min_temperature         Nullable(Int8),
    average_wind_speed      Nullable(Int8),

    pickup_nyct2010_gid     Nullable(Int8),
    pickup_ctlabel          Nullable(String),
    pickup_borocode         Nullable(Int8),
    pickup_boroname         Nullable(String),
    pickup_ct2010           Nullable(String),
    pickup_boroct2010       Nullable(String),
    pickup_cdeligibil       Nullable(FixedString(1)),
    pickup_ntacode          Nullable(String),
    pickup_ntaname          Nullable(String),
    pickup_puma             Nullable(String),

    dropoff_nyct2010_gid    Nullable(UInt8),
    dropoff_ctlabel         Nullable(String),
    dropoff_borocode        Nullable(UInt8),
    dropoff_boroname        Nullable(String),
    dropoff_ct2010          Nullable(String),
    dropoff_boroct2010      Nullable(String),
    dropoff_cdeligibil      Nullable(String),
    dropoff_ntacode         Nullable(String),
    dropoff_ntaname         Nullable(String),
    dropoff_puma            Nullable(String)
) ENGINE = MergeTree(pickup_date, pickup_datetime, 8192);

Keyin birinchi server klasterdagi barcha uchta tugunni ko'rishiga ishonch hosil qilaman.

SELECT *
FROM system.clusters
WHERE cluster = 'perftest_3shards'
FORMAT Vertical;
Row 1:
──────
cluster:          perftest_3shards
shard_num:        1
shard_weight:     1
replica_num:      1
host_name:        172.30.2.192
host_address:     172.30.2.192
port:             9000
is_local:         1
user:             default
default_database:
Row 2:
──────
cluster:          perftest_3shards
shard_num:        2
shard_weight:     1
replica_num:      1
host_name:        172.30.2.162
host_address:     172.30.2.162
port:             9000
is_local:         0
user:             default
default_database:

Row 3:
──────
cluster:          perftest_3shards
shard_num:        3
shard_weight:     1
replica_num:      1
host_name:        172.30.2.36
host_address:     172.30.2.36
port:             9000
is_local:         0
user:             default
default_database:

Keyin birinchi serverda sxemaga asoslangan yangi jadvalni aniqlayman trips_mergetree_third va taqsimlangan dvigateldan foydalanadi.

CREATE TABLE trips_mergetree_x3
    AS trips_mergetree_third
    ENGINE = Distributed(perftest_3shards,
                         default,
                         trips_mergetree_third,
                         rand());

Keyin MergeTree asosidagi jadvaldagi ma'lumotlarni barcha uchta serverga ko'chirib olaman. Quyidagi 34 daqiqa 44 soniyada yakunlandi.

INSERT INTO trips_mergetree_x3
    SELECT * FROM trips_mergetree;

Yuqoridagi operatsiyadan so'ng, men ClickHouse-ga maksimal saqlash darajasi belgisidan uzoqlashish uchun 15 daqiqa vaqt berdim. Ma'lumotlar kataloglari uchta serverning har birida mos ravishda 264 GB, 34 GB va 33 GB bo'ldi.

ClickHouse klasterining ishlashini baholash

Keyingi ko'rgan narsam jadvaldagi har bir so'rovni bir necha marta bajarishni ko'rgan eng tez vaqt edi trips_mergetree_x3.

$ clickhouse-client --host=0.0.0.0

Quyidagi 2.449 soniyada yakunlandi.

SELECT cab_type, count(*)
FROM trips_mergetree_x3
GROUP BY cab_type;

Quyidagi 0.691 soniyada yakunlandi.

SELECT passenger_count,
       avg(total_amount)
FROM trips_mergetree_x3
GROUP BY passenger_count;

Quyidagi 0 soniyada yakunlandi.

SELECT passenger_count,
       toYear(pickup_date) AS year,
       count(*)
FROM trips_mergetree_x3
GROUP BY passenger_count,
         year;

Quyidagi 0.983 soniyada yakunlandi.

SELECT passenger_count,
       toYear(pickup_date) AS year,
       round(trip_distance) AS distance,
       count(*)
FROM trips_mergetree_x3
GROUP BY passenger_count,
         year,
         distance
ORDER BY year,
         count(*) DESC;

Taqqoslash uchun, men bir xil so'rovlarni faqat birinchi serverda joylashgan MergeTree-ga asoslangan jadvalda bajardim.

Bitta ClickHouse tugunining ishlashini baholash

Keyingi ko'rgan narsam jadvaldagi har bir so'rovni bir necha marta bajarishni ko'rgan eng tez vaqt edi trips_mergetree_x3.

Quyidagi 0.241 soniyada yakunlandi.

SELECT cab_type, count(*)
FROM trips_mergetree
GROUP BY cab_type;

Quyidagi 0.826 soniyada yakunlandi.

SELECT passenger_count,
       avg(total_amount)
FROM trips_mergetree
GROUP BY passenger_count;

Quyidagi 1.209 soniyada yakunlandi.

SELECT passenger_count,
       toYear(pickup_date) AS year,
       count(*)
FROM trips_mergetree
GROUP BY passenger_count,
         year;

Quyidagi 1.781 soniyada yakunlandi.

SELECT passenger_count,
       toYear(pickup_date) AS year,
       round(trip_distance) AS distance,
       count(*)
FROM trips_mergetree
GROUP BY passenger_count,
         year,
         distance
ORDER BY year,
         count(*) DESC;

Natijalar bo'yicha mulohazalar

Bu birinchi marta protsessorga asoslangan bepul ma'lumotlar bazasi sinovlarimda GPU-ga asoslangan ma'lumotlar bazasidan ustun bo'ldi. O'shandan beri GPU-ga asoslangan ma'lumotlar bazasi ikki marta qayta ko'rib chiqildi, ammo ClickHouse-ning bitta tugunda taqdim etgan ishlashi juda ta'sirli.

Shu bilan birga, taqsimlangan dvigatelda 1-so'rovni bajarishda qo'shimcha xarajatlar kattaroq tartibni tashkil qiladi. Umid qilamanki, men ushbu post bo'yicha tadqiqotimda biror narsani o'tkazib yubordim, chunki klasterga ko'proq tugunlar qo'shganimda so'rovlar vaqtini kamaytirishni ko'rish yaxshi bo'lardi. Biroq, boshqa so'rovlarni bajarishda unumdorlik taxminan 2 barobarga oshgani juda yaxshi.

ClickHouse-ni saqlash va hisoblashni ajratish imkoniyatiga ega bo'lish yo'lida rivojlanishini ko'rish yaxshi bo'lardi, shunda ular mustaqil ravishda o'lchovni o'tkazishlari mumkin. O'tgan yili qo'shilgan HDFS yordami bunga qadam bo'lishi mumkin. Hisoblash nuqtai nazaridan, agar bitta so'rovni klasterga ko'proq tugunlarni qo'shish orqali tezlashtirish mumkin bo'lsa, unda ushbu dasturiy ta'minotning kelajagi juda porloq.

Ushbu postni o'qishga vaqt ajratganingiz uchun tashakkur. Men Shimoliy Amerika va Yevropadagi mijozlarga konsalting, arxitektura va amaliyotni rivojlantirish xizmatlarini taklif qilaman. Agar siz mening takliflarim sizning biznesingizga qanday yordam berishi mumkinligini muhokama qilishni istasangiz, iltimos, orqali men bilan bog'laning LinkedIn.

Manba: www.habr.com

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