Zero Downtime Deployment ndi Databases

Nkhaniyi ikufotokoza mwatsatanetsatane momwe mungathetsere zovuta zokhudzana ndi database potumiza. Tikuwuzani zomwe zingachitike pamapulogalamu anu opanga ngati mutayesa kutumiza popanda kukonzekera koyambirira. Kenako tidutsa magawo omwe akufunika kuti asakhale ndi nthawi yopumira (pafupifupi. njira: kupitilira - zero kutsika). Chotsatira cha ntchito zathu chidzakhala kugwiritsa ntchito kusintha kwa database komwe sikungagwirizane m'mbuyo-kumbuyo.

Ngati mukufuna kumvetsetsa zitsanzo za ma code kuchokera m'nkhaniyi, mutha kuwapeza GitHub.

Mau oyamba

Zero downtime kutumiza

Ndi zachinsinsi bwanji zero downtime kutumiza? Mutha kunena kuti izi ndi pamene pulogalamu yanu yatumizidwa m'njira yoti mutha kuwonetsa bwino pulogalamu yatsopano yopangira, pomwe wogwiritsa sazindikira kusapezeka kwake. Kuchokera kwa wogwiritsa ntchito ndi kampani, iyi ndiye njira yabwino kwambiri yotumizira chifukwa imalola kuti zatsopano zikhazikitsidwe komanso kuti nsikidzi zikhazikitsidwe popanda kusokoneza.

Kodi kukwaniritsa izi? Pali njira zingapo, iyi ndi imodzi mwazo:

• perekani mtundu 1 wautumiki wanu
• kusamutsa database
• Ikani mtundu #2 wautumiki wanu molumikizana ndi mtundu #1
• mukangowona mtundu wa nambala 2 ukugwira ntchito momwe ziyenera kukhalira, chotsani Nambala 1
• zachitika!

Zosavuta, sichoncho? Tsoka ilo, sizophweka, ndipo tidzayang'ana mwatsatanetsatane pambuyo pake. Tsopano tiyeni tiwone njira ina yodziwika bwino yotumizira - buluu wobiriwira.

Kodi mudamvapo za buluu wobiriwira kutumizidwa? Cloud Foundry imapangitsa izi kukhala zosavuta kwambiri. Ingoyang'anani nkhaniyi, pamene tikufotokoza izi mwatsatanetsatane. Kuti tifotokoze mwachidule, tiyeni tikukumbutseni momwe mungapangire buluu wobiriwira:

• onetsetsani kuti makope awiri a code yanu yopanga ("buluu" ndi "green") amagwira ntchito;
• kuwongolera magalimoto onse ku chilengedwe cha buluu, i.e. kotero kuti ma URL opanga amaloze pamenepo;
• tumizani ndikuyesa kusintha konse kwa ntchito pamalo obiriwira;
• sinthani ma ulalo kuchokera ku buluu kupita ku malo obiriwira

Kutumiza kobiriwira kwa buluu ndi njira yomwe imakupatsani mwayi wowonetsa zatsopano popanda kudandaula za kusweka kwa kupanga. Izi ndichifukwa choti ngakhale zitachitika zinazake, mutha kubwereranso kumalo am'mbuyomu ndikungoyang'ana chosinthira.

Mutawerenga zonse zomwe zili pamwambapa, mutha kufunsa funso: Kodi zero downtime ikukhudzana bwanji ndi Blue green deployment?

Eya, ali ndi zambiri zofanana, popeza kusunga makope aŵiri a malo ofanana kumafuna khama loŵirikiza kaŵiri kuwasamalira. Ichi ndichifukwa chake matimu ena amati Martin Fowler, tsatirani kusiyanasiyana kwa njira iyi:

Njira ina ndikugwiritsa ntchito nkhokwe yomweyo, kupanga masiwichi obiriwira abuluu pa intaneti ndi magawo a domain. Mwanjira iyi, nkhokwe nthawi zambiri imakhala vuto, makamaka mukafunika kusintha schema yake kuti muthandizire pulogalamu yatsopano.

Ndipo apa tabwera ku vuto lalikulu m'nkhaniyi. Nawonsomba. Tiyeni tionenso mawuwa.

kusamutsa database.

Tsopano muyenera kudzifunsa funsoli - bwanji ngati kusintha kwa database sikukugwirizana ndi kumbuyo? Kodi mtundu wanga woyamba wa pulogalamuyi sutha? M'malo mwake, izi ndi zomwe zidzachitike ...

Chifukwa chake, ngakhale pali phindu lalikulu la zero downtime / buluu kutumizidwa kobiriwira, makampani amakonda kutsatira njira zotsatirazi zotetezedwa potumiza mapulogalamu awo:

• konzani phukusi ndi mtundu watsopano wa pulogalamuyo
• kutseka pulogalamu yomwe ikuyenda
• yendetsani zolemba kuti musamutse database
• perekani ndikuyambitsa pulogalamu yatsopano

Munkhaniyi, tifotokoza mwatsatanetsatane momwe mungagwirire ntchito ndi nkhokwe yanu ndi ma code kuti mutengere mwayi paziro zotsitsa nthawi.

Nkhani za database

Ngati muli ndi pulogalamu yopanda malire yomwe siyisunga deta iliyonse mu database, mutha kupeza zero downtime deployment nthawi yomweyo. Tsoka ilo, mapulogalamu ambiri amafunika kusunga deta kwinakwake. Ichi ndichifukwa chake muyenera kuganiza kawiri musanapange kusintha kulikonse kwa dera. Tisanalowe mwatsatanetsatane wamomwe mungasinthire schema kuti palibe kutsitsa nthawi, tiyeni tiyang'ane kaye pa schema yosinthira.

Ndondomeko yomasulira

M'nkhaniyi tigwiritsa ntchito Flyway ngati chida chowongolera mtundu (pafupifupi. Kumasulira: tikukamba za kusamuka kwa database). Mwachilengedwe, tidzalembanso pulogalamu ya Spring Boot yomwe yapanga chithandizo cha Flyway ndipo idzachita kusamuka kwa schema ndikukhazikitsa zomwe zikugwiritsidwira ntchito. Mukamagwiritsa ntchito Flyway, mutha kusunga zolembedwa zosamukira mufoda yanu yamapulojekiti (mwachisawawa mu classpath:db/migration). Apa mutha kuwona chitsanzo cha mafayilo osamuka ngati awa

└── db
 └── migration
     ├── V1__init.sql
     ├── V2__Add_surname.sql
     ├── V3__Final_migration.sql
     └── V4__Remove_lastname.sql

Muchitsanzo ichi tikuwona zolemba za 4 zosamuka zomwe, ngati sizinachitike m'mbuyomu, zidzachitidwa chimodzi pambuyo pa chimzake ntchito ikayamba. Tiyeni tiwone imodzi mwamafayilo (V1__init.sql) mwachitsanzo.

CREATE TABLE PERSON (
id BIGINT GENERATED BY DEFAULT AS IDENTITY,
first_name varchar(255) not null,
last_name varchar(255) not null
);

insert into PERSON (first_name, last_name) values ('Dave', 'Syer');

Chilichonse chimadzifotokozera chokha: mutha kugwiritsa ntchito SQL kutanthauzira momwe database yanu iyenera kusinthidwa. Kuti mumve zambiri za Spring Boot ndi Flyway, onani Spring Boot Docs.

Pogwiritsa ntchito chida chowongolera magwero ndi Spring Boot, mumapeza zabwino ziwiri:

• mumalekanitsa zosintha za database ndikusintha ma code
• Kusamuka kwa database kumachitika limodzi ndi kutulutsidwa kwa pulogalamu yanu, i.e. ndondomeko yanu yotumizira idzakhala yosavuta

Kuthetsa mavuto a database

Mu gawo lotsatira la nkhaniyi, tiyang'ana pa kuyang'ana njira ziwiri zosinthira database.

• kusagwirizana m'mbuyo
• kuyanjana mmbuyo

Yoyamba idzaonedwa ngati chenjezo loti simuyenera kuchita zero downtime deployment popanda kukonzekera koyambirira ... Yachiwiri ikupereka yankho la momwe mungapangire ntchito popanda nthawi yopuma komanso panthawi imodzimodziyo kusunga kugwirizanitsa kumbuyo.

Pulojekiti yathu yomwe tikhala tikugwirapo ikhala pulogalamu yosavuta ya Spring Boot Flyway yomwe ili nayo Person с first_name и last_name mu database (pafupifupi. kumasulira: Person ndi tebulo ndi first_name и last_name - awa ndi minda momwemo). Tikufuna kutchula dzina last_name в surname.

Zongoganizira

Tisanalowe mwatsatanetsatane, pali malingaliro angapo omwe tiyenera kupanga pakugwiritsa ntchito kwathu. Chotsatira chachikulu chomwe tikufuna kukwaniritsa chidzakhala njira yosavuta.

Kalata. Business PRO-TIP. Njira zophweka zimatha kukupulumutsirani ndalama zambiri pothandizira (pamene mumapeza anthu ambiri ogwira ntchito ku kampani yanu, mumasunga ndalama zambiri)!

Palibe chifukwa chobweza database

Izi zimathandizira njira yotumizira (zobweza zina za database ndizosatheka, monga kufufuta). Timakonda kubweza mapulogalamu okha. Mwanjira iyi, ngakhale mutakhala ndi nkhokwe zosiyanasiyana (mwachitsanzo, SQL ndi NoSQL), payipi yanu yotumizira idzawoneka chimodzimodzi.

Ziyenera kukhala zotheka NTHAWI ZONSE kubweza pulogalamuyo mtundu umodzi kubwerera (palibenso)

Kubweza kuyenera kuchitika kokha ngati kuli kofunikira. Ngati pali vuto mu mtundu wapano womwe suli wokonzeka kukhazikika, tiyenera kubwerera ku mtundu waposachedwa kwambiri. Tikuganiza kuti mtundu waposachedwa uwu ndi wam'mbuyo. Kusunga ma code ndi nkhokwe yogwirizana ndi kutulutsa kopitilira kumodzi kungakhale kovuta kwambiri komanso kokwera mtengo.

Kalata. Kuti muwerenge kwambiri, m'nkhaniyi tisintha mtundu waukulu wa pulogalamuyi.

Gawo 1: Dziko Loyamba

Mtundu wa App: 1.0.0
Mtundu wa DB: v1

ndemanga

Ichi chidzakhala chikhalidwe choyambirira cha ntchito.

Kusintha kwa database

DB ili ndi last_name.

CREATE TABLE PERSON (
id BIGINT GENERATED BY DEFAULT AS IDENTITY,
first_name varchar(255) not null,
last_name varchar(255) not null
);

insert into PERSON (first_name, last_name) values ('Dave', 'Syer');

Kusintha kwa ma code

Pulogalamuyi imasunga data ya Munthu mkati last_name:

/*
 * Copyright 2012-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package sample.flyway;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
public class Person {
    @Id
    @GeneratedValue
    private Long id;
    private String firstName;
    private String lastName;

    public String getFirstName() {
        return this.firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return this.lastName;
    }

    public void setLastName(String lastname) {
        this.lastName = lastname;
    }

    @Override
    public String toString() {
        return "Person [firstName=" + this.firstName + ", lastName=" + this.lastName
                + "]";
    }
}

Kusinthana kwazambiri kosagwirizana

Tiyeni tiwone chitsanzo cha momwe mungasinthire dzina lazambiri:

Chisamaliro. Chitsanzo chotsatirachi chidzaphwanya zinthu mwadala. Tikuwonetsa izi kuti tiwonetse vuto la kuyanjana kwa database.

Mtundu wa App: 2.0.0.BAD

Mtundu wa DB: v2bad

ndemanga

Zosintha zomwe zasintha SAKUTIlola kuti tiziyendetsa zochitika ziwiri (zakale ndi zatsopano) nthawi imodzi. Choncho, kutumizidwa kwa zero kudzakhala kovuta kukwaniritsa (ngati zongoganizira zikuganiziridwa, sizingatheke).

Kuyesa kwa A/B

Zomwe zikuchitika pano ndikuti tili ndi mtundu wa pulogalamu 1.0.0, kutumizidwa mukupanga, ndi database v1. Tiyenera kugwiritsa ntchito chitsanzo chachiwiri cha pulogalamuyo, mtundu 2.0.0.BAD, ndikusintha database kuti v2bad.

Masitepe:

1. mawonekedwe atsopano a pulogalamu yamtunduwu atumizidwa 2.0.0.BADzomwe zimasintha database v2bad
2. mu nkhokwe v2bad ndime last_name kulibenso - idasinthidwa kukhala surname
3. Dongosolo la database ndi zosintha zamapulogalamu zidayenda bwino ndipo nthawi zina zikuyenda 1.0.0, ena - mkati 2.0.0.BAD. Chilichonse chikugwirizana ndi database v2bad
4. zitsanzo zonse za Baibulo 1.0.0 ayamba kuponya zolakwika chifukwa adzayesa kuyika deta muzanja last_nameamene kulibenso
5. zitsanzo zonse za Baibulo 2.0.0.BAD adzagwira ntchito popanda mavuto

Monga mukuwonera, ngati tisintha m'mbuyo zosagwirizana ndi database ndikugwiritsa ntchito, kuyesa kwa A / B sikutheka.

Kubweza ntchito

Tiyerekeze kuti titayesa kupanga kutumiza kwa A/B (pafupifupi. pa.: wolemba mwina amatanthauza kuyesa kwa A / B apa) tinaganiza kuti tifunika kubweza pulogalamuyo ku mtunduwo 1.0.0. Tinene kuti sitikufuna kubwezeretsanso database.

Masitepe:

1. timayimitsa chitsanzo cha pulogalamuyo 2.0.0.BAD
2. database ikadali v2bad
3. kuyambira Baibulo 1.0.0 samamvetsa chomwe chiri surname, tiwona zolakwika
4. gehena yasweka, sitingabwererenso

Monga mukuwonera, ngati tisintha m'mbuyo zosagwirizana ndi database ndi kugwiritsa ntchito, sitingathe kubwereranso ku mtundu wakale.

Zolemba za script

Backward incompatible scenario:

01) Run 1.0.0
02) Wait for the app (1.0.0) to boot
03) Generate a person by calling POST localhost:9991/person to version 1.0.0
04) Run 2.0.0.BAD
05) Wait for the app (2.0.0.BAD) to boot
06) Generate a person by calling POST localhost:9991/person to version 1.0.0 <-- this should fail
07) Generate a person by calling POST localhost:9992/person to version 2.0.0.BAD <-- this should pass

Starting app in version 1.0.0
Generate a person in version 1.0.0
Sending a post to 127.0.0.1:9991/person. This is the response:

{"firstName":"b73f639f-e176-4463-bf26-1135aace2f57","lastName":"b73f639f-e176-4463-bf26-1135aace2f57"}

Starting app in version 2.0.0.BAD
Generate a person in version 1.0.0
Sending a post to 127.0.0.1:9991/person. This is the response:

curl: (22) The requested URL returned error: 500 Internal Server Error

Generate a person in version 2.0.0.BAD
Sending a post to 127.0.0.1:9995/person. This is the response:

{"firstName":"e156be2e-06b6-4730-9c43-6e14cfcda125","surname":"e156be2e-06b6-4730-9c43-6e14cfcda125"}

Kusintha kwa database

Migration script yomwe imatchedwanso last_name в surname

Zolemba za Flyway:

CREATE TABLE PERSON (
id BIGINT GENERATED BY DEFAULT AS IDENTITY,
first_name varchar(255) not null,
last_name varchar(255) not null
);

insert into PERSON (first_name, last_name) values ('Dave', 'Syer');

Script yomwe imatchedwanso last_name.

-- This change is backward incompatible - you can't do A/B testing
ALTER TABLE PERSON CHANGE last_name surname VARCHAR;

Kusintha kwa ma code

Tasintha dzina lamunda lastName pa surname.

Kusintha dzina lazambiri m'njira yobwerera m'mbuyo

Izi ndizochitika zofala kwambiri zomwe tingakumane nazo. Tiyenera kupanga zobwerera mmbuyo zosagwirizana. Tatsimikizira kale kuti potumiza zero-downtime, sitiyenera kungogwiritsa ntchito kusamuka kwa database popanda njira zowonjezera. Mu gawo ili la nkhaniyi, tipanga ma deployments 3 a pulogalamuyo pamodzi ndi kusamuka kwa database kuti tikwaniritse zomwe mukufuna ndikusunga zobwerera m'mbuyo.

Kalata. Kumbukirani kuti tili ndi database ya mtundu v1. Lili ndi mizati first_name и last_name. Tiyenera kusintha last_name pa surname. Tilinso ndi mtundu wa pulogalamu 1.0.0, zomwe sizinagwiritsidwebe ntchito surname.

Gawo 2: Onjezani surname

Mtundu wa App: 2.0.0
Mtundu wa DB: v2

ndemanga

Powonjezera ndime yatsopano ndikukopera zomwe zili mkati mwake, timapanga zosinthika zobwerera m'mbuyo zomwe zimagwirizana. Nthawi yomweyo, ngati tibweza JAR kapena kukhala ndi JAR yakale yomwe ikuyenda, sichitha kuphedwa.

Tikutulutsa mtundu watsopano

Masitepe:

1. sinthani database kuti mupange gawo latsopano surname. Tsopano mtundu wanu wa DB v2
2. kukopera deta kuchokera last_name в surname. Samalanikuti ngati muli ndi zambiri izi, muyenera kuganizira kusamuka kwa batch!
3. lembani malamulo omwe agwiritsidwa ntchito ZOWIRI и новыйndi akale ndime. Tsopano mtundu wa pulogalamu yanu 2.0.0
4. werengani mtengo wagawolo surname, ngati sichoncho nullkapena ku last_namengati surname zomwe sizinafotokozedwe. Mutha kufufuta getLastName() kuchokera ku code, chifukwa idzatulutsa null pamene mukubweza pulogalamu yanu kuchokera 3.0.0 mpaka 2.0.0.

Ngati mukugwiritsa ntchito Spring Boot Flyway, masitepe awiriwa adzachitika poyambitsa mtundu 2.0.0 mapulogalamu. Ngati mugwiritsa ntchito chida chosinthira nkhokwe pamanja, muyenera kuchita zinthu ziwiri zosiyana kuti muchite izi (choyamba sinthani mtundu wa db pamanja ndikuyika pulogalamu yatsopanoyo).

Ndikofunika. Kumbukirani kuti gawo lopangidwa kumene SAYENERA kukhala OSAKHALA. Ngati mubweza, pulogalamu yakale sadziwa zagawo latsopano ndipo sangayiyikire panthawiyo Insert. Koma ngati muwonjezera izi ndipo db yanu idzakhala v2, izi zidzafunika kukhazikitsa mtengo wagawo latsopano. Zomwe zidzatsogolera kuphwanya malamulo.

Ndikofunika. Muyenera kuchotsa njira getLastName(), chifukwa mu Baibulo 3.0.0 Palibe lingaliro la gawo mu code last_name. Izi zikutanthauza kuti null idzakhazikitsidwa pamenepo. Mutha kusiya njira ndikuwonjezera macheke null, koma njira yabwinoko ingakhale kuonetsetsa kuti muzomveka getSurname() mwasankha mtengo wolondola wopanda ziro.

Kuyesa kwa A/B

Zomwe zikuchitika pano ndikuti tili ndi mtundu wa pulogalamu 1.0.0, yotumizidwa pakupanga, ndi database mu v1. Tiyenera kuyikanso chitsanzo chachiwiri cha pulogalamuyo 2.0.0zomwe zidzasinthire database v2.

Masitepe:

1. mawonekedwe atsopano a pulogalamu yamtunduwu atumizidwa 2.0.0zomwe zimasintha database v2
2. Pakadali pano zopempha zina zidasinthidwa ndi mawonekedwe 1.0.0
3. kusinthidwa kunali kopambana ndipo muli ndi machitidwe angapo ogwiritsira ntchito mtunduwo 1.0.0 ndi Mabaibulo ena 2.0.0. Aliyense amalumikizana ndi database mu v2
4. Baibulo 1.0.0 sichigwiritsa ntchito gawo la surname mu database, koma mtunduwo 2.0.0 amagwiritsa. Sasokonezana, ndipo pasakhale zolakwa.
5. Baibulo 2.0.0 imasunga zidziwitso mugawo lakale ndi latsopano, kuwonetsetsa kuti zimagwirizana

Ndikofunika. Ngati muli ndi mafunso omwe amawerengera zinthu kutengera mindandanda yakale/yatsopano, muyenera kukumbukira kuti tsopano muli ndi zikhalidwe zobwereza (mwina zimasamukabe). Mwachitsanzo, ngati mukufuna kuwerengera kuchuluka kwa ogwiritsa ntchito omwe dzina lawo lomaliza (chilichonse chomwe gawoli limatchedwa) adayamba ndi chilembocho A, ndiye mpaka kusamutsidwa kwa data kumalizidwa (old → new column) mutha kukhala ndi data yosagwirizana ngati mungafunse gawo latsopano.

Kubweza ntchito

Tsopano tili ndi mtundu wa pulogalamu 2.0.0 ndi database in v2.

Masitepe:

1. bwezeretsani pulogalamu yanu kuti isinthe 1.0.0.
2. Baibulo 1.0.0 sichigwiritsa ntchito gawo mu database surname, kotero kubwezeretsa kuyenera kukhala kopambana

DB kusintha

Malo osungirako zinthuwa ali ndi gawo lotchedwa last_name.

Flyway source script:

CREATE TABLE PERSON (
id BIGINT GENERATED BY DEFAULT AS IDENTITY,
first_name varchar(255) not null,
last_name varchar(255) not null
);

insert into PERSON (first_name, last_name) values ('Dave', 'Syer');

Onjezani script surname.

Chisamaliro. Kumbukirani kuti SUNGAWONZE zolepheretsa ZONSE ZA NULL pagawo lomwe mukuwonjezera. Ngati mubweza JAR, mtundu wakale sudzakhala ndi chidziwitso chokhudza gawo lowonjezeredwa ndipo mudzangoyiyika kukhala NULL. Ngati pali malire otero, ntchito yakale idzangosweka.

-- NOTE: This field can't have the NOT NULL constraint cause if you rollback, the old version won't know about this field
-- and will always set it to NULL
ALTER TABLE PERSON ADD surname varchar(255);

-- WE'RE ASSUMING THAT IT'S A FAST MIGRATION - OTHERWISE WE WOULD HAVE TO MIGRATE IN BATCHES
UPDATE PERSON SET PERSON.surname = PERSON.last_name

Kusintha kwa ma code

Timasunga deta ngati last_name, ndi surname. Nthawi yomweyo timawerenga kuchokera last_name, popeza gawoli ndilofunika kwambiri. Panthawi yotumiza, zopempha zina zikhoza kukonzedwa ndi zochitika zomwe sizinasinthidwe.

/*
 * Copyright 2012-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package sample.flyway;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
public class Person {
    @Id
    @GeneratedValue
    private Long id;
    private String firstName;
    private String lastName;
    private String surname;

    public String getFirstName() {
        return this.firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    /**
     * Reading from the new column if it's set. If not the from the old one.
     *
     * When migrating from version 1.0.0 -> 2.0.0 this can lead to a possibility that some data in
     * the surname column is not up to date (during the migration process lastName could have been updated).
     * In this case one can run yet another migration script after all applications have been deployed in the
     * new version to ensure that the surname field is updated.
     *
     * However it makes sense since when looking at the migration from 2.0.0 -> 3.0.0. In 3.0.0 we no longer
     * have a notion of lastName at all - so we don't update that column. If we rollback from 3.0.0 -> 2.0.0 if we
     * would be reading from lastName, then we would have very old data (since not a single datum was inserted
     * to lastName in version 3.0.0).
     */
    public String getSurname() {
        return this.surname != null ? this.surname : this.lastName;
    }

    /**
     * Storing both FIRST_NAME and SURNAME entries
     */
    public void setSurname(String surname) {
        this.lastName = surname;
        this.surname = surname;
    }

    @Override
    public String toString() {
        return "Person [firstName=" + this.firstName + ", lastName=" + this.lastName + ", surname=" + this.surname
                + "]";
    }
}

Khwerero 3: Kuchotsa last_name pa code

Mtundu wa App: 3.0.0

Mtundu wa DB:v3

ndemanga

Zindikirani pa. last_name.

Powonjezera gawo latsopano ndikukopera zomwe zili mkati mwake, tidapanga zosintha zomwe zimagwirizana ndi database. Komanso, ngati tibweza JAR kapena kukhala ndi JAR yakale yomwe ikuyenda, sichitha kuphedwa.

Kubweza ntchito

Pano tili ndi mtundu wa pulogalamu 3.0.0 ndi database v3. Baibulo 3.0.0 sichisunga deta ku last_name. Izi zikutanthauza kuti mu surname zidziwitso zaposachedwa kwambiri zimasungidwa.

Masitepe:

1. bwezeretsani pulogalamu yanu kuti isinthe 2.0.0.
2. Baibulo 2.0.0 amagwiritsa ntchito ndi last_name и surname.
3. Baibulo 2.0.0 adzatenga surname, ngati si ziro, mwinamwake -last_name

Kusintha kwa database

Palibe zosintha zamapangidwe mu database. Malemba otsatirawa akuchitidwa kuti asamuke komaliza kwa data yakale:

-- WE'RE ASSUMING THAT IT'S A FAST MIGRATION - OTHERWISE WE WOULD HAVE TO MIGRATE IN BATCHES
-- ALSO WE'RE NOT CHECKING IF WE'RE NOT OVERRIDING EXISTING ENTRIES. WE WOULD HAVE TO COMPARE
-- ENTRY VERSIONS TO ENSURE THAT IF THERE IS ALREADY AN ENTRY WITH A HIGHER VERSION NUMBER
-- WE WILL NOT OVERRIDE IT.
UPDATE PERSON SET PERSON.surname = PERSON.last_name;

-- DROPPING THE NOT NULL CONSTRAINT; OTHERWISE YOU WILL TRY TO INSERT NULL VALUE OF THE LAST_NAME
-- WITH A NOT_NULL CONSTRAINT.
ALTER TABLE PERSON MODIFY COLUMN last_name varchar(255) NULL DEFAULT NULL;

Kusintha kwa ma code

Zindikirani pa.: Kufotokozera kwa chipikachi kunakoperanso molakwika ndi wolemba kuchokera pa sitepe 2. Mogwirizana ndi malingaliro a nkhaniyi, kusintha kwa code pa sitepe iyi kuyenera kukhala ndi cholinga chochotsamo zinthu zomwe zimagwira ntchito ndi gawoli. last_name.

Timasunga deta ngati last_name, ndi surname. Kuwonjezera apo, timawerenga kuchokera pagawo last_name, popeza ndilofunika kwambiri. Panthawi yotumiza, zopempha zina zitha kukonzedwa ndi chochitika chomwe sichinasinthidwebe.

/*
 * Copyright 2012-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package sample.flyway;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
public class Person {
    @Id
    @GeneratedValue
    private Long id;
    private String firstName;
    private String surname;

    public String getFirstName() {
        return this.firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getSurname() {
        return this.surname;
    }

    public void setSurname(String lastname) {
        this.surname = lastname;
    }

    @Override
    public String toString() {
        return "Person [firstName=" + this.firstName + ", surname=" + this.surname
                + "]";
    }
}

Khwerero 4: Kuchotsa last_name ku database

Mtundu wa App: 4.0.0

Mtundu wa DB: v4

ndemanga

Chifukwa chakuti Baibulo code 3.0.0 sanagwiritse ntchito ndime last_name, palibe choipa chomwe chidzachitike panthawi ya kuphedwa ngati tibwerera ku 3.0.0 mutachotsa mzati ku database.

Zolemba za script

We will do it in the following way:

01) Run 1.0.0
02) Wait for the app (1.0.0) to boot
03) Generate a person by calling POST localhost:9991/person to version 1.0.0
04) Run 2.0.0
05) Wait for the app (2.0.0) to boot
06) Generate a person by calling POST localhost:9991/person to version 1.0.0
07) Generate a person by calling POST localhost:9992/person to version 2.0.0
08) Kill app (1.0.0)
09) Run 3.0.0
10) Wait for the app (3.0.0) to boot
11) Generate a person by calling POST localhost:9992/person to version 2.0.0
12) Generate a person by calling POST localhost:9993/person to version 3.0.0
13) Kill app (3.0.0)
14) Run 4.0.0
15) Wait for the app (4.0.0) to boot
16) Generate a person by calling POST localhost:9993/person to version 3.0.0
17) Generate a person by calling POST localhost:9994/person to version 4.0.0

Starting app in version 1.0.0
Generate a person in version 1.0.0
Sending a post to 127.0.0.1:9991/person. This is the response:

{"firstName":"52b6e125-4a5c-429b-a47a-ef18bbc639d2","lastName":"52b6e125-4a5c-429b-a47a-ef18bbc639d2"}

Starting app in version 2.0.0

Generate a person in version 1.0.0
Sending a post to 127.0.0.1:9991/person. This is the response:

{"firstName":"e41ee756-4fa7-4737-b832-e28827a00deb","lastName":"e41ee756-4fa7-4737-b832-e28827a00deb"}

Generate a person in version 2.0.0
Sending a post to 127.0.0.1:9992/person. This is the response:

{"firstName":"0c1240f5-649a-4bc5-8aa9-cff855f3927f","lastName":"0c1240f5-649a-4bc5-8aa9-cff855f3927f","surname":"0c1240f5-649a-4bc5-8aa9-cff855f3927f"}

Killing app 1.0.0

Starting app in version 3.0.0

Generate a person in version 2.0.0
Sending a post to 127.0.0.1:9992/person. This is the response:
{"firstName":"74d84a9e-5f44-43b8-907c-148c6d26a71b","lastName":"74d84a9e-5f44-43b8-907c-148c6d26a71b","surname":"74d84a9e-5f44-43b8-907c-148c6d26a71b"}

Generate a person in version 3.0.0
Sending a post to 127.0.0.1:9993/person. This is the response:
{"firstName":"c6564dbe-9ab5-40ae-9077-8ae6668d5862","surname":"c6564dbe-9ab5-40ae-9077-8ae6668d5862"}

Killing app 2.0.0

Starting app in version 4.0.0

Generate a person in version 3.0.0
Sending a post to 127.0.0.1:9993/person. This is the response:

{"firstName":"cbe942fc-832e-45e9-a838-0fae25c10a51","surname":"cbe942fc-832e-45e9-a838-0fae25c10a51"}

Generate a person in version 4.0.0
Sending a post to 127.0.0.1:9994/person. This is the response:

{"firstName":"ff6857ce-9c41-413a-863e-358e2719bf88","surname":"ff6857ce-9c41-413a-863e-358e2719bf88"}

DB kusintha

Zochepa v3 timangochotsa mzati last_name ndi kuwonjezera zoletsa zomwe zikusowa.

-- REMOVE THE COLUMN
ALTER TABLE PERSON DROP last_name;

-- ADD CONSTRAINTS
UPDATE PERSON SET surname='' WHERE surname IS NULL;
ALTER TABLE PERSON ALTER COLUMN surname VARCHAR NOT NULL;

Kusintha kwa ma code

Palibe zosintha pamakhodi.

Pomaliza

Tinagwiritsa ntchito bwino kusintha kwa dzina lazambiri lomwe silingagwirizane m'mbuyo popanga maulendo angapo obwerera m'mbuyo. M'munsimu muli chidule cha zomwe zachitika:

1. kutumizidwa kwa mtundu wa pulogalamu 1.0.0 с v1 schema database (dzina lazambiri = last_name)
2. kutumizidwa kwa mtundu wa pulogalamu 2.0.0, zomwe zimasunga data mkati last_name и surname. Pulogalamuyi ikuchokera last_name. Nawonso database ili mu mtundu v2okhala ndi mizati ngati last_name, ndi surname. surname ndi kopi last_name. (Dziwani: ndime iyi siyenera kukhala ndi choletsa chachabechabe)
3. kutumizidwa kwa mtundu wa pulogalamu 3.0.0, zomwe zimangosunga deta mkati surname ndipo amawerenga kuchokera ku surname. Ponena za database, kusamuka komaliza kukuchitika last_name в surname. Komanso malire OSAKHALA kuchotsedwa last_name. Nawonso database ili mu mtundu v3
4. kutumizidwa kwa mtundu wa pulogalamu 4.0.0 - palibe kusintha komwe kumapangidwa ku code. Kutumiza kwa database v4, zomwe zimachotsa last_name. Apa mutha kuwonjezera zopinga zilizonse zomwe zikusowa ku database.

Potsatira njirayi mutha kubweza mtundu umodzi nthawi zonse popanda kuphwanya mayendedwe a database/mapulogalamu.

kachidindo

Ma code onse omwe agwiritsidwa ntchito m'nkhaniyi akupezeka pa Github. Pansipa pali kufotokozera kowonjezera.

Mapulani

Mukamaliza kupanga chosungira, mudzawona chikwatu chotsatirachi.

├── boot-flyway-v1              - 1.0.0 version of the app with v1 of the schema
├── boot-flyway-v2              - 2.0.0 version of the app with v2 of the schema (backward-compatible - app can be rolled back)
├── boot-flyway-v2-bad          - 2.0.0.BAD version of the app with v2bad of the schema (backward-incompatible - app cannot be rolled back)
├── boot-flyway-v3              - 3.0.0 version of the app with v3 of the schema (app can be rolled back)
└── boot-flyway-v4              - 4.0.0 version of the app with v4 of the schema (app can be rolled back)

Zolemba

Mutha kuyendetsa zolembedwa zomwe zafotokozedwa m'munsimu, zomwe zikuwonetsa zosintha zomwe zimagwirizana m'mbuyo komanso zosagwirizana ndi database.

Kukawona vuto ndi kusintha mmbuyo n'zogwirizana, thamanga:

./scripts/scenario_backward_compatible.sh

Ndipo kuwona vuto ndi zosintha zam'mbuyo zosagwirizana, thamanga:

./scripts/scenario_backward_incompatible.sh

Spring Boot Chitsanzo Flyway

Zitsanzo zonse zatengedwa kuchokera Spring Boot Sample Flyway.

Mutha kuyang'ana http://localhost:8080/flyway, pali mndandanda wa zolemba.

Chitsanzochi chikuphatikizanso cholumikizira cha H2 (pa http://localhost:8080/h2-console) kotero mutha kuwona momwe database yanu ilili (zosasintha za jdbc URL ndi jdbc:h2:mem:testdb).

Komanso

• Makhalidwe a Database Refactoring
• Kupitiliza kopitilira

Werenganinso zolemba zina pa blog yathu:

• Kubernetes: chifukwa chiyani kuli kofunikira kukhazikitsa kasamalidwe kazinthu zamakina?
• Mapaipi a Tekton - mapaipi amtundu wa Kubernetes
• Kupanga ma module amphamvu a Nginx
• Chidziwitso cha Hashicorp Consul's Kubernetes Authorization
• Kodi kusamuka kuchokera ku ClickHouse popanda chilolezo kupita ku ClickHouse ndi chilolezo kudatsogolera chiyani?
• Blue-Green Deployment of Spring applications ndi Nginx web server

Source: www.habr.com