Uthini umahluko phakathi kwecron kunye necrond? Funda iimfihlo zemisebenzi eyahlukeneyo kwi-1 ngomzuzu

ukhona Linux Qwalasela imisebenzi ecwangcisiweyo kwisistim, kodwa uzive ubhidekile phakathi kwe "cron" kunye ne "crond"?

Ewe, abantu abaninzi baya kuzibuza:"Nguwuphi umahluko phakathi kwezi zimbini?" Nangona ekhangeleka njengamawele, xa ehlolisiswa kakuhle, kukho umahluko ochuliweyo kodwa obalulekileyo phakathi kwawo.

Eli nqaku liza kukuthatha nzulu kwiimpawu zabo ezizodwa kunye nemigaqo yokusebenza.

Yintoni icron?

masiqale ngayo Cron Okokuqala, eli gama kufuneka uqhelene nawe.

cron ngokwenene iseti epheleleyo Inkqubo yokucwangcisa umsebenzi ocwangcisiweyo, ogama lakhe livela kwingcambu yesiGrike "chronos”, okuthetha ixesha.

inkqubo yecronIngumcwangcisi wemisebenzi ecwangcisiweyo kwiinkqubo zeLinux, esetyenziselwa ukwenza ngokuzenzekelayo imisebenzi ethile kwiindawo ezithile ngexesha.

Umzekelo, unokucwangcisa izikripthi zogcino eziza kwenziwa rhoqo kusasa, jonga imeko yenkqubo rhoqo ngeyure, njl.

cron core ukusebenza

Umsebenzi ophambili wecron kukwenza ngokuzenzekelayo ulawulo kunye nokwenziwa kwemisebenzi yenkqubo le misebenzi ihlala ibizwa ngokuba ".imisebenzi ecwangcisiweyo” okanye “Umsebenzi ocwangcisiweyo”.

Inkqubo yecron iya kufunda icrontab 文件(itafile yecron), ezi fayile ziqulethe iishedyuli zomsebenzi kunye noluhlu lwemiyalelo, kwaye i-cron iya kwenza ngokuzenzekelayo le misebenzi ngamaxesha acwangcisiweyo ngokusekelwe kwizicwangciso kwifayile yecrontab.

Kunokuthiwa okocron "ngumcwangcisi" wokucwangcisa umsebenzi ocwangcisiweyo, uxanduva lokuseka iishedyuli zayo yonke imisebenzi.

Sebenzisa umyalelo wecrontab

Kwiinkqubo zeLinux, inkqubo yecron iqulathe crontab umyalelo wokulawula. dlula crontab Imiyalelo, unokongeza, uhlele kwaye ucime imisebenzi ecwangcisiweyo.

使用 crontab -e Umyalelo wokungena kwimodi yokuhlela, unokongeza imisebenzi ofuna ukuyenza kwitafile yecron, ifomathi yile ilandelayo:

* * * * * /path/to/command

Isimboli ngasinye "*" simele iyunithi yexesha elahlukileyo, njengemizuzu, iiyure, iintsuku, iinyanga kunye neeveki. Ngolu lungelelwaniso lwexesha, unokulawula xa imisebenzi yenziwe.

Yintoni icrond?

Ngoku ukuba siyawuqonda umbono wecron, makhe sijonge crond. Le "iqhawe elisemva kwemifanekiso" yenkqubo yecron.

icrond yeyenkqubo yecron idaemon, yinkqubo eqhuba ngokuqhubekayo ngasemva kwaye inoxanduva lokujonga ixesha lenkqubo kunye nokwenza imisebenzi ebekwe yinkqubo yecron.

uxanduva lukacrond

Inkqubo yecrond iya kuqala ngokuzenzekelayo xa inkqubo iqala kwaye ihlala isebenza ngasemva Umsebenzi wayo kuphela kukuphumeza imisebenzi kwifayile yecrontab ngexesha elichaziweyo.

Kunokuthiwa okocrond "ngumenzi" wenkqubo yecron,

Ngaphandle kwenkqubo yecrond, inkqubo yecron iya kuphulukana namandla okwenza imisebenzi ecwangcisiweyo.

Kwiinkqubo zeLinux, ungasebenzisa lo myalelo ulandelayo ukujonga ukuba inkqubo yecrond iyasebenza:

ps -ef | grep crond

Ukuba inkqubo yecrond ayisebenzi, yonke imisebenzi ecwangcisiweyo ayizukwenziwa. Ke ngoko, kubalulekile ukugcina inkqubo yecrond isebenza ngokuqhelekileyo.

Ubudlelwane phakathi kwecron kunye necrond: iinkonzo kunye nabaphathi

Ukuze siqonde ngcono ubudlelwane phakathi kwecron kunye necrond, sinokusebenzisa aUbomiumzekelo kwi.

Umfanekiso: unomntu ogama lakhe "Incwadi encinci ebomvu” isicelo, esiyinkqubo enkulu evumela abasebenzisi ukuba bajonge baze bapapashe umxholo ngamaxesha athile;

Emva kwesi sicelo, kukho inkqubo ebizwa ngokuba yi "Xiaohong Guardian", enoxanduva lokupapasha umxholo ngasemva.

I-cron ifana "nencwadi encinci ebomvu", kwaye i-crond "ngumgcini omncinci obomvu".

Ukushwankathela umahluko phakathi kwecron kunye necrond:

• Cron: Unoxanduva lokuqulunqa nokulawula iishedyuli zomsebenzi, kwaye "yingqondo" yokucwangcisa umsebenzi ocwangcisiweyo.
• crond: Inkqubo ye-daemon yangasemva, "engumenzi" wemisebenzi ecwangcisiweyo kwaye enze imisebenzi ngokweshedyuli kwitafile yecron.

Ukujonga ngale ndlela, i-cron yinkqubo iyonke, kwaye i-crond yinkqubo eyenza imisebenzi kwinkqubo.

ifayile yecrontab: uluhlu lwemisebenzi yecron

Isiseko sokwenziwa kwenkqubo yecron ayinakwahlulwa ifayile yecrontab, kulapho inkqubo yecron igcina khona iishedyuli zomsebenzi.

Umsebenzisi ngamnye (kubandakanywa nomsebenzisi weengcambu) unokuba nefayile yakhe ezimeleyo yecrontab yokulawula imisebenzi yakhe ecwangcisiweyo.

singasebenzisa crontab -l umyalelo wokujonga uluhlu lomsebenzi wangoku, okanye sebenzisa crontab -e ukuhlela umsebenzi.

crontab ifayile syntax

Kwifayile yecrontab, umgca ngamnye umele umsebenzi, kwaye ifomathi yomgca ngamnye imi ngolu hlobo lulandelayo:

分钟 小时 日期 月份 星期 命令

Umzekelo, lo msebenzi ulandelayo umele ukuphumeza iskripthi sogcino ngo-2 am yonke imihla:

0 2 * * * /usr/local/bin/backup.sh

Lo mzekelo olula ubonisa amandla okuzenzekelayo okuzenzekelayo kwenkqubo yecron.

I-cron kunye ne-crond: intsebenziswano yabo ngasemva kwe-scenes

Kumsebenzi wangempela wenkqubo, i-cron kunye ne-crond ayinakwahlulwa. I-cron inoxanduva lokudala nokulawula iishedyuli zomsebenzi, ngelixa i-crond ibeka iliso ngokuqhubekayo ixesha kwaye iqinisekisa ukuba imisebenzi yenziwa ngexesha elichaziweyo.

Nanini na ixesha lenkqubo lifikelela kwixesha elimiselweyo lomsebenzi, i-crond iya "kuvuka" kwaye yenze umsebenzi.

Kutheni sifuna i-crond daemon?

Ubukho becrond buqinisekisa ukuba imisebenzi yenziwa ngexesha Iyakuqala ngokuzenzekelayo ngalo lonke ixesha inkqubo iqala kwaye iqhubeka isebenza.

Ukuba icrond iyeka ukusebenza, yonke imisebenzi ekwinkqubo yecron ayizukwazi ukuphumeza. Ke ngoko, ukusebenza okuqhelekileyo kwe-crond daemon kubalulekile kulawulo oluzenzekelayo lwenkqubo.

Iimeko zesicelo kulawulo lwenkqubo yemihla ngemihla

Ukudibanisa i-cron kunye ne-crond isetyenziswa ngokubanzi kulawulo lwenkqubo, ngakumbi kwiindawo zeseva. Ezi zilandelayo zezinye iimeko zesicelo eziqhelekileyo:

1. ugcino oluzenzekelayo: Ngokusebenzisa i-cron, unokucwangcisa umncedisi ukuba agcine idatha rhoqo yonke imihla okanye ngeveki.
2. Ukucoca ngokuzenzekelayo: Cwangcisa ukucocwa rhoqo kweefayile zelog ukukhusela indawo yedisk yomncedisi ekuzalisweni.
3. Ukubeka iliso kunye nokothusa: Yenza rhoqo iisheke zezempilo zenkqubo nge-cron kwaye uthumele ii-imeyile ze-alarm xa izinto ezingaqhelekanga zifunyenwe.

Ukungaqondi kakuhle phakathi kwecron kunye necrond: Imibuzo ebuzwa rhoqo kunye neempendulo

Kutheni umsebenzi wecron ungaphunyezwa?

Abantu abaninzi baya kufumanisa ukuba imisebenzi ye-cron abayisetayo ayenziwanga njengoko bekulindelekile Izizathu zinokubandakanya oku kulandelayo:

1. inkqubo yecrond ayiqaliswanga: Nceda uqiniseke ukuba i-crond isebenza ngokuqhelekileyo.
2. Impazamo yokumisela umsebenzi: Khangela ukuba i-syntax yefayile yecrontab ichanekile.
3. ingxaki yendlela: Qinisekisa ukuba umyalelo ochaziweyo kunye neendlela zescript zichanekile.

Uyiqala njani kwakhona inkqubo yecrond?

Ukuba inkqubo yecrond ayiqhelekanga, ungasebenzisa lo myalelo ulandelayo ukuyiqalisa kwakhona:

sudo service crond restart

Lo myalelo uya kuphinda uqalise inkonzo yecrond ukuqinisekisa ukuba yonke imisebenzi iqhutywa ngokwesiqhelo.

Isiphelo: Ukubaluleka kwecron kunye necrond

Intsebenziswano egqibeleleyo phakathi kwecron kunye necrond ivumela inkqubo yeLinux ukuba iqhube ngokuzenzekelayo imisebenzi ngaphandle kokungenelela kwabantu, iphucula kakhulu amandla olawulo oluzenzekelayo.

cron isebenza njengenkqubo yokucwangcisa ixesha ukwenza izicwangciso, kwaye icrond isebenza njengenkqubo yedaemon enoxanduva lokwenza imisebenzi.

Kunokuthiwa ukuba ezi zimbini ziyancedisana kwaye zakha ngokudibeneyo inkqubo yokulawula umsebenzi onamandla kwaye oguquguqukayo.

Kusetyenziso lwemihla ngemihla, ukuqonda umahluko kunye nokusetyenziswa kwecron kunye necrond kunokukwenza ukhululeke ngakumbi kulawulo lweseva kwaye ufezekise imisebenzi esebenzayo.

Kwixesha elizayo, unokufunda ngakumbi malunga nokusetyenziswa okuphambili kwenkqubo yecron ukuqhubela phambili nokwenza ngcono inkqubo yakho yolawulo lwenkqubo.

I-cron kunye ne-crond ngokuqinisekileyo ngamaqabane alungileyo ukuba wonke umlawuli weLinux kufuneka abe nawo.