1.1 milyar taksi lelungan: 108-inti kluster ClickHouse

Terjemahan artikel disiapake khusus kanggo siswa kursus kasebut Data Engineer.

1.1 milyar taksi lelungan: 108-inti kluster ClickHouse

clickhouse minangka basis data kolom open source. Iki minangka lingkungan sing apik ing ngendi atusan analis bisa nggoleki data rinci kanthi cepet, sanajan puluhan milyar rekaman anyar dilebokake saben dina. Biaya infrastruktur kanggo ndhukung sistem kasebut bisa nganti $ 100 saben taun, lan bisa uga setengah gumantung saka panggunaan. Ing sawijining wektu, instalasi ClickHouse saka Yandex Metrics ngemot 10 triliun cathetan. Saliyane Yandex, ClickHouse uga sukses karo Bloomberg lan Cloudflare.

Rong taun kepungkur aku ngginakaken analisis komparatif database nggunakake siji mesin, lan dadi paling cepet free lunak database aku wis tau ndeleng. Wiwit iku, pangembang ora mandheg nambahake fitur, kalebu dhukungan kanggo kompresi Kafka, HDFS lan ZStandard. Paling taun padha ditambahaké support kanggo cara komprèsi cascading, lan delta-saka-delta coding dadi bisa. Nalika ngompres data seri wektu, nilai gauge bisa dikompres kanthi apik nggunakake enkoding delta, nanging kanggo counter luwih apik nggunakake enkoding delta-by-delta. Kompresi sing apik wis dadi kunci kanggo kinerja ClickHouse.

ClickHouse kasusun saka 170 ewu baris kode C ++, ora kalebu perpustakaan pihak katelu, lan minangka salah sawijining basis kode basis data sing disebarake paling cilik. Ing comparison, SQLite ora ndhukung distribusi lan kasusun saka 235 ewu baris kode C. Ing tulisan iki, 207 engineers wis nyumbang kanggo ClickHouse, lan intensitas commits wis nambah bubar.

Ing Maret 2017, ClickHouse wiwit tumindak changelog minangka cara sing gampang kanggo nglacak pembangunan. Dheweke uga nyuwil file dokumentasi monolitik dadi hirarki file adhedhasar Markdown. Masalah lan fitur dilacak liwat GitHub, lan umume piranti lunak dadi luwih gampang diakses ing sawetara taun kepungkur.

Ing artikel iki, Aku bakal njupuk dipikir ing kinerja kluster ClickHouse ing AWS EC2 nggunakake prosesor 36-inti lan panyimpenan NVMe.

UPDATE: Seminggu sawise nerbitake kiriman iki, aku nyoba maneh tes kanthi konfigurasi sing luwih apik lan entuk asil sing luwih apik. Kiriman iki wis dianyari kanggo nggambarake owah-owahan kasebut.

Ngluncurake Kluster AWS EC2

Aku bakal nggunakake telung c5d.9xlarge EC2 kedadean kanggo kirim iki. Saben wong ngemot 36 CPU virtual, 72 GB RAM, 900 GB panyimpenan NVMe SSD lan ndhukung jaringan 10 Gigabit. Padha regane $1,962/jam saben ing wilayah eu-kulon-1 nalika mlaku ing dikarepake. Aku bakal nggunakake Ubuntu Server 16.04 LTS minangka sistem operasi.

Firewall wis diatur supaya saben mesin bisa komunikasi karo saben liyane tanpa watesan, lan mung alamat IPv4 sandi whitelisted dening SSH ing kluster.

Drive NVMe ing status kesiapan operasional

Kanggo ClickHouse bisa digunakake, aku bakal nggawe sistem file ing format EXT4 ing drive NVMe ing saben server.

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

Sawise kabeh wis diatur, sampeyan bisa ndeleng titik gunung lan 783 GB papan kasedhiya ing saben sistem.

$ 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

Dataset sing bakal digunakake ing tes iki yaiku mbucal data sing digawe saka 1.1 milyar taksi sing dijupuk ing New York City sajrone nem taun. Ing blog Siji Milyar Taxi Trips ing Redshift rincian carane aku diklumpukake set data iki. Padha disimpen ing AWS S3, supaya aku bakal ngatur AWS CLI karo akses lan kunci rahasia.

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

Aku bakal nyetel watesan panjalukan bebarengan klien kanggo 100 supaya file download luwih cepet saka setelan gawan.

$ aws configure set 
    default.s3.max_concurrent_requests 
    100

Aku bakal ngundhuh dataset nitih taksi saka AWS S3 lan nyimpen ing drive NVMe ing server pisanan. Set data iki ~ 104GB ing format CSV sing dikompres GZIP.

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

Instalasi ClickHouse

Aku bakal nginstal distribusi OpenJDK kanggo Java 8 amarga dibutuhake kanggo mbukak Apache ZooKeeper, sing dibutuhake kanggo instalasi ClickHouse sing disebarake ing kabeh telung mesin.

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

Banjur aku nyetel variabel lingkungan JAVA_HOME.

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

Aku banjur bakal nggunakake sistem manajemen paket Ubuntu kanggo nginstal ClickHouse 18.16.1, glances lan ZooKeeper ing kabeh telung mesin.

$ 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

Aku bakal nggawe direktori kanggo ClickHouse lan uga nindakake sawetara konfigurasi overrides ing kabeh telung server.

$ 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

Iki minangka overrides konfigurasi sing bakal digunakake.

<?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>

Aku banjur bakal mbukak ZooKeeper lan server ClickHouse ing kabeh telung mesin.

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

Ngunggah data menyang ClickHouse

Ing server pisanan aku bakal nggawe tabel trip (trips), sing bakal nyimpen dataset lelungan taksi nggunakake mesin Log.

$ 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;

Aku banjur extract lan mbukak saben file CSV menyang tabel trip (trips). Ing ngisor iki rampung ing 55 menit lan 10 detik. Sawise operasi iki, ukuran direktori data ana 134 GB.

$ 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)

Kacepetan impor yaiku 155 MB konten CSV sing ora dikompres per detik. Aku curiga iki amarga bottleneck ing dekompresi GZIP. Bisa uga luwih cepet unzip kabeh file gzip ing podo karo nggunakake xargs banjur mbukak data unzip. Ing ngisor iki ana katrangan babagan apa sing dilaporake sajrone proses ngimpor CSV.

$ 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

Aku bakal mbebasake spasi ing drive NVMe kanthi mbusak file CSV asli sadurunge nerusake.

$ sudo rm -fr /ch/csv

Ngonversi menyang Formulir Column

Mesin Log ClickHouse bakal nyimpen data ing format berorientasi baris. Kanggo pitakon data luwih cepet, aku ngowahi menyang format kolom nggunakake mesin MergeTree.

$ clickhouse-client --host=0.0.0.0

Ing ngisor iki rampung ing 34 menit lan 50 detik. Sawise operasi iki, ukuran direktori data 237 GB.

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;

Iki minangka output tampilan sajrone operasi:

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)

Ing tes pungkasan, sawetara kolom diowahi lan diitung maneh. Aku nemokake sawetara fungsi kasebut ora bisa digunakake maneh kaya sing dikarepake ing dataset iki. Kanggo ngatasi masalah iki, aku mbusak fungsi sing ora cocog lan mbukak data tanpa ngowahi menyang jinis sing luwih granular.

Distribusi data ing kluster

Aku bakal mbagekke data ing kabeh telung kelenjar kluster. Kanggo miwiti, ing ngisor iki aku bakal nggawe tabel ing kabeh telung mesin.

$ 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);

Banjur aku bakal nggawe manawa server pisanan bisa ndeleng kabeh telung kelenjar ing kluster.

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:

Banjur aku bakal nemtokake tabel anyar ing server pisanan sing adhedhasar skema trips_mergetree_third lan nggunakake mesin Distribusi.

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

Aku banjur bakal nyalin data saka MergeTree adhedhasar tabel kanggo kabeh telung server. Ing ngisor iki rampung ing 34 menit lan 44 detik.

INSERT INTO trips_mergetree_x3
    SELECT * FROM trips_mergetree;

Sawise operasi ing ndhuwur, aku menehi ClickHouse 15 menit kanggo pindhah saka tandha tingkat panyimpenan maksimum. Direktori data rampung dadi 264 GB, 34 GB lan 33 GB ing saben telung server kasebut.

Evaluasi kinerja kluster ClickHouse

Sing dakdeleng sabanjure yaiku wektu paling cepet aku ndeleng saben pitakon ing meja kaping pirang-pirang trips_mergetree_x3.

$ clickhouse-client --host=0.0.0.0

Ing ngisor iki rampung ing 2.449 detik.

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

Ing ngisor iki rampung ing 0.691 detik.

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

Ing ngisor iki rampung ing 0 detik.

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

Ing ngisor iki rampung ing 0.983 detik.

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;

Kanggo mbandhingake, aku mbukak pitakon sing padha ing tabel basis MergeTree sing mung ana ing server pisanan.

Evaluasi kinerja siji simpul ClickHouse

Sing dakdeleng sabanjure yaiku wektu paling cepet aku ndeleng saben pitakon ing meja kaping pirang-pirang trips_mergetree_x3.

Ing ngisor iki rampung ing 0.241 detik.

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

Ing ngisor iki rampung ing 0.826 detik.

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

Ing ngisor iki rampung ing 1.209 detik.

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

Ing ngisor iki rampung ing 1.781 detik.

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;

Renungan ing asil

Iki pisanan sing free basis CPU basis data bisa outperform basis GPU ing tes sandi. Database basis GPU kasebut wis ngalami rong revisi wiwit saiki, nanging kinerja sing dikirim ClickHouse ing simpul siji pancen apik banget.

Ing wektu sing padha, nalika nglakokake Query 1 ing mesin sing disebarake, biaya overhead minangka urutan gedhene sing luwih dhuwur. Mugi aku ora kejawab soko ing riset kanggo kirim iki amarga iku bakal becik kanggo ndeleng kaping query mudhun nalika aku nambah kelenjar liyane menyang kluster. Nanging, apik banget yen nalika nindakake pitakon liyane, kinerja mundhak udakara 2 kali.

Luwih becik ndeleng ClickHouse berkembang dadi bisa misahake panyimpenan lan ngitung supaya bisa ukuran kanthi mandiri. Dhukungan HDFS, sing ditambahake taun kepungkur, bisa dadi langkah menyang iki. Ing babagan komputasi, yen query siji bisa dicepetake kanthi nambahake simpul liyane menyang kluster, mula masa depan piranti lunak iki cerah banget.

Matur nuwun kanggo njupuk wektu kanggo maca kirim iki. Aku nawakake konsultasi, arsitektur, lan layanan pangembangan praktik kanggo klien ing Amerika Utara lan Eropa. Yen sampeyan pengin ngrembug babagan carane saran bisa mbantu bisnis sampeyan, hubungi kula liwat LinkedIn.

Source: www.habr.com

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