mariadb - Synchronous vs Asynchronous Clustering -



mariadb - Synchronous vs Asynchronous Clustering -

i reading mariadd knowledge base of operations on galera cluster , came across this:

the basic difference between synchronous , asynchronous replication "synchronous" guarantees if changes happened on 1 node of cluster, happened on other nodes "synchronously", or @ same time. "asynchronous" gives no guarantees delay between applying changes on "master" node , propagation of changes "slave" nodes. delay can short or long. implies if master node crashes, of latest changes may lost

with lastly sentence, have understood though updates on slave in asynchronous cluster setup not performed @ same time, logs these updates bin log file updates beingness made on master. in case master crashes before info passed on slave, updates still go ahead when master restored since bin log file logged updates. can please tell me if understanding wrong , clarify on matter me please. thanks.

in illustration of normal replication pair, slave grab after master comes back. assuming master come back, wouldn't lose info if master permanently dead, info lost. knowledge base of operations article mention talking replication delay , not overall integrity of replication stream.

with normal replication, if slave io thread (the part gets replication events master) able maintain master, slave may lose couple seconds if master crashes. however, if cannot maintain , illustration 1 hr behind, slave lose access 1 hr of data. way lose access info on slave if have max relay log size set , reached.

galera makes sure write sent every node in cluster before committed on of nodes 1 time node write done on commits write, of other nodes commit same write. galera, writes happen @ same time on every node. losing node @ time during normal operation not cause info loss.

mariadb mysql-cluster galera

Comments

Post a Comment

Popular posts from this blog

Delphi change the assembly code of a running process -

Delphi change the assembly code of a running process - i'm trying alter address 00741fa5 has push test.009e721c . alter push test.009e71c8 . procedure callback; asm force $9e71c8 end; procedure tform2.btn1click(sender: tobject); var ppid :dword; pprocess : cardinal; begin getwindowthreadprocessid(findwindow(nil,pchar('test')), @ppid); pprocess := openprocess(process_all_access, false, ppid); injectasm(pprocess, $741fa5, 10, integer(@callback), 0); end; here injectasm function (with error checking) function injectasm(process: longword; injectaddress, injectsize, codeaddress, codesize : integer): pointer; var csize, rsize : integer; replaced : array of byte; jmp : array [0..4] of byte; jmpaddress : integer; nopv : byte; : integer; nbr: ulong_ptr; begin //injectsize must equal or greater 5, because need space our //(far) jmp wwxxyyzz instruction //if there's no space, inject in place of few instructions if injectsize ...
Read more

json - Hibernate and Jackson (java.lang.IllegalStateException: Cannot call sendError() after the response has been committed) -

json - Hibernate and Jackson (java.lang.IllegalStateException: Cannot call sendError() after the response has been committed) - hello have problem hibernate , jackson. have 2 pojos @entity @table(name = "users") public class user implements serializable { static final long serialversionuid = 4235637833262722256l; @id @generatedvalue private int id; @column(name = "creation_date") private date creationdate; @column(name = "first_name") private string firstname; @column(name = "last_name") private string lastname; @version @column(name = "version") private int version; @column(name = "e_mail") private string email; @column(name = "enabled") private boolean enabled; @column(name = "login") private string login; @column(name = "password") private string password; @jsonmanagedreference("role") @onetomany(mappedby = "user", cascade = cascadetype.all,fetch = fetchtyp...
Read more

C++ 11 "class" keyword -

C++ 11 "class" keyword - i've started using c++ 11 little bit more , have few questions on special uses of class keyword. know it's used declare class, there's 2 instances have seen don't understand: method<class t>(); and class class_name *var; why precede typename keyword class in first example, , keyword pointer in sec example? that known elaborated type specifier , necessary when class name "shadowed" or "hidden" , need explicit. class t { }; // love of god don't t t; t t2; if compiler smart, give these warnings: main.cpp:15:5: error: must utilize 'class' tag refer type 't' in scope t t2; ^ class main.cpp:14:7: note: class 't' hidden non-type declaration of 't' here t t; ^ if class not defined, deed forwards declaration. for example: template <typename t> void method() { using type = typename t::value_type; } method...
Read more