Questions tagged [replication]
Replication is the process of sharing any level of information so as to ensure consistency between redundant hardware/software resources to improve reliability, fault-tolerance, and accessibility
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How repeatable read isolation level and others are implemented in distributed/replicated databases?
I'm studying distributed systems/DBs and I'm struggling understanding isolation levels when we talk about distributed systems.
Avoiding problems like dirty read, non-repeatable read, phantom reads, ...
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How do I sync MySQL DB table
I have 9 MySQL servers in different environments. One of them is in the testing server. That one will be the first server if I have to make the change.
Is there any way I can sync the table from the ...
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PostgreSQL replication checking pg_stat_subscription more than 1 row
I'm new to DB replication.
I performed a replication task on 3 production DB.
On the first 2 DBs (low size) on the subscriber side, they only have 1 row result when i query pg_stat_subscription. On ...
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logical replication initial phase
I am about doing replication for 16 millions record. Just want to ask about the initial phase of logical replication :
Do I need to copy the initial table from publisher to subscriber first ? Or is ...
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Resume MySQL / MariaDB replication from master logs
Master server crashed and slave was running behind. I can not boot the master to resume the replication and retrieve the data lost. Is there a way to resume the replication directly from the log files?...
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How to enable replication filters in AWS Aurora 2 (5.7.mysql_aurora.2.10.2)?
I enabled binary log replication in Aurora to replicate from one cluster to another. I went to use the CHANGE REPLICATION FILTER command but get a 1227 error saying I must have the SUPER privilege, ...
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How to debug a huge MySQL replication lag?
We have an AWS RDS and a corresponding Replica. Once or twice a month the replication lags and does not recover from its own. Our "solution" is to create a new replica and delete the old one....
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Transactional replication deadlock during setup
I'm encountering a problem setting up transactional replication between SQL Server 2017 and an Azure SQL database on a high throughput system.
When trying to add any of the bigger, higher traffic ...
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The best way to initialize table before logical replication
I am in the middle of setting up logical replication between 2 physical servers.
It involves 2 tables from the master with millions of rows. One table got 15 millions, and another one is 7 millions. ...
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MongoDB OplogStart Missing
I understand that some times MongoDB secondary data becomes stale at which point, we need to perform an init sync from the Primary instance.
But sometimes we see error logs that look like this:
2022-...
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SQL server replication conflicts
Once per week, a snapshot publication is done from a database "myDB" in PROD to "myDB" in PREPROD.
Now in PREPROD we set up a transactional replication between "myDB" to ...
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slave on logical replication does not get update real time
I successfully started logical replication on a testing environment. I generate insert on the master for some 60K records using procedure. While the insert process is running, i monitor the slave ...
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Can a geo replica Azure SQL be turned into a read-write database?
Can a geo replica Azure SQL be turned into a read-write database? The idea is that instead of restoring a prod database into another database which might take a long time, have a geo replica as normal ...
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PostgreSQL replication options
community!
I am wondering if there are any new extensions/solutions which can replicate not the entire PG cluster but by database?
Logical replication is not an option.
For example, I want my primary ...
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How to determine server with most recent transactions when re-starting MySQL Group Replications?
We're implementing our first database cluster with MySQL Group Replication, and are setting up the procedure for handling the re-start if all member servers of the group fail due to something like a ...
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Replication in SQL Server by Merging a Publisher and Subscriber
I have 2 databases, A and B.
database A contains a subset of database B. I want to replicate any changes on database A (insert, update, delete one way replication) to database B without affecting any ...
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is it possible to change postgresql schema on receiver using logical replication?
I have a PostgreSQL 12 database set up to follow a remote database (version 12) using logical replication.
I do not control the sender database.
I need to perform queries on the DB filtering records ...
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Replication between two Cloud Services
Is it possible to implement SQL Server Replication between two disparate cloud services?
For instance, if I have an instance running in Amazon's AWS Cloud Service and another instance running in ...
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Logical Replication and Archiving
Is it necessary to turn on archiving when replication is being used ?
I notice that replication generates WAL files. Yes it can grow large, but what if hard disk space is not a problem ?
I'm using ...
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I there a way to decode pglogical transaction to find table name in trouble?
I've set up pglogical replication between postgresql 9.x and 13.x and it was replicating (initially syncing the 200G database) just fine for quite some time.
Then it got stuck at some point, showing ...
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In Azure, what's the best setup for creating a development db with a production db? Replication, mirroring, copying, copy then sync, etc?
Currently in Azure, I have a website (app service) pointing a database (Sql Server). So far so good! Everything is still in development so nothing is live yet. I use EF code first migration with all ...
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postgres archiver not working
I have a problem with archiving. Here are some parameters :
`SELECT COUNT(*) FROM pg_ls_dir('pg_wal') WHERE pg_ls_dir ~ '^[0-9A-F]{24}'`; -- 4048 files
checkpoint_completion_target : -- 0.9
...
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Monitor logical replication using LSN
How do I monitor a logical replication in Postgresql 12 by seeing the lsn ?
What I have done :
Inspect some colomns on Publisher and Subscriber.
Publisher side :
select * from pg_stat_replication; -- ...
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How can I determine which database a replication subscription belongs to?
Following along from https://stackoverflow.com/questions/68720250/cannot-drop-subscription-from-postgresql
It seems in order to drop the subscription, you first need to connect to the associated ...
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Limiting subscription to just one table only
Icreate a Publication using :
CREATE PUBLICATION TEST_publication2 FOR TABLE public.Table1;
Then I create a Subscription using this
CREATE SUBSCRIPTION test_mysub
CONNECTION 'host=10.100.5.55 port=...
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WAL files management
I want to have advice about WAL management. I am expecting a large numbers of wal files (the database is very large and it has like 30 - 40 millions of records in totals) since I am setting up a ...
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FAIL creating subscription postgresql
I want to setup logical replication between 2 PGs 12 on different servers, one being the Publisher and the other Subscriber.
On the Publisher side, I have this settings as follows:
hot_standby = ON
...
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Replication instantly fails with 1032 error; Coordinator stopped because there were error(s) in the worker(s)
I have two databases, which I'm attempting to configure in a master-slave relationship (the eventual goal is to set them as master-master, but I'll settle for getting master-slave working at this ...
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How to disable MYSQL Replication?
I have 2 databases which are replicating each other with no issues. I required a test database server and to avoid installing OS etc, I started a new image of one of the servers (with different ...
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How to find out the lock details in mysql replica
Currently we are deleting old records from the multiple tables. In the async replication one of the replica is lagging. From the show engine innodb status\G
2 lock struct(s), heap size 1136, 1 row ...
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POSTGRESQL table replication between 2 servers
I want to to replicate A TABLE from one server A to another B so that A and B always in-sync.
This table on server A has like 4 - 5 million rows, whereas the table B is empty.
What I want to do is ...
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Read Postgres CDC data with Logical Replication via Pgoutput plugin and decode it into textual format
Background: We are running Postgres v13.4 and have enabled logical replication for reading CDC data for a select few tables. We are using the pgoutput plugin and the basic setup is working fine.
Query:...
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Multi master vs leader-follower
Sorry if I ask this basic question. I am reading different articles and trying to understand how it works.
Lets suppose I have two master DB(MySQL) in two different availability zone and two different ...
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MySQL Replication is online, but stalls with no errors or large transactions
Have a replica that runs MySql 5.6 Replication. It has been running without issue for a long time. Now replication is running, but it pauses on a transaction and will not move until you issue a stop/...
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How to replicate between On-Premises and Azure in Mongodb
I have three 3 node cluster on-premises ( 1 Primary and 2 Secondary ). I have same 3 node cluster in AZURE ( 1 Primary and 2 Secondary ) with same version and data but with different FQDN in azure. ...
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Pgpool for HA of Postgres with repmgr switchover. Pgpool haw to follow primary
I'm trying to setup a highly available postgres (13) cluster(3 servers) with streaming replication.
I first tried native replication and then decided to use repmgr to manage this so I could use the ...
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Cannot connect to PostgreSQL replica [duplicate]
I can't to connect to PostgreSQL replica.
When I try to connect to PostgreSQL replica it shows error message:
psql: error: FATAL: canceling statement due to conflict with recovery
DETAIL: User query ...
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How to rollback to earlier SQL Server version without data loss after SQL Server upgrade
We are planning for SQL Server 2019 upgrade from SQL Server 2014 version. One of the requirement from the business owners is that we should be able to fall back to earlier version without data loss ...
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Drop Subscriber at SQL Transactional replication
We have SQL Transactional pull replication:
Publisher and Distributor are at the same server - ServerA.
It publicates Publication1.
Pull Subscribers to Publication1 are - ServerB, ServerC and ...
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Replicate MySQL table to MariaDB for System Versioning
We have some tables in an operational and busy MySQL database (AWS RDS) for which we require system versioning for some of the tables. (point-in-time queries)
Is it possible to somehow replicate the ...
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MySQL Replication with Data Transformation and Replicant-specific Data
I have two MySQL 8.0.23 RDS's - one "Production" RDS that actual users use, and one "Performance" RDS that is used for performance testing.
These databases have the same schema and ...
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SQL Database Replication
I have requirement with below for SQL database replication.
I have two separate SQL database servers on same network, one will be used as primary and another one as secondary.
Primary is a central ...
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Can we use a mongodb 4.3.3 and mongodb 2.6.5 in same replica set?
we are running a mongo 2.6.5, 5 member replica set on CentOS and are looking to upgrade to 4.3.3. We do not use sharding. The tricky part for us is that we operate a service and can't have scheduled ...
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Enabling replication in MySQL in fresh database
We have a legacy TokuDB database that we would like to begin migrating to a new engine. Unfortunately taking the db offline for migration is not feasible. We also can reprocess all the data in the ...
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Finding the MySQL binlog positions to restore replication
I have a large database where replication became broken (a query to delete rows ran on the slave directly by mistake)
The decision was taken to restore the slave from the master. I've made an export ...
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Postgresql Replication issues of clarity
In an effort to document myself I examined a few sources; these two from the official docs and this external one seemed promising
Now the latter one seems to be updated in 2020, but refers to version ...
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Is wal_keep_segments required with streaming replication when archive and restore commands are set?
I have a 2 node postresql(12.9) cluster with streaming replication enabled. I have also set the archive and restore commands which I verified is working as expected. No replication slots or ...
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Why is restoring a fresh database from a backup failing due to a duplicate key error?
I'm trying to build a replica from an active database with no downtime for replication purposes.
I run the following statement to get a backup, avoid locking the tables, and flush the logs so that the ...
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SQL Server replication between standard and developer editions
I have one SQL Server Standard (2019), I want to add one server to developper (not used by production so the version if developper), it's possible to replicate data ? what is the best methode ? we ...
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Report (log) of each transaction on SQL Server Replication?
I've configured a transactional type of Replication between two SQL Servers. Since it's a project that it's still under review on my side I have only selected a couple of articles for the replication. ...
