quorum backup

The Quorum mechanism is one of the many protocols and mechanisms used in the design of distributed systems to solve the problem of reliability and data consistency. We simply introduce it through a read-write model in a distributed system. the reading and writing model in distributed system Distributed system is composed of multiple nodes (referring to a server, storage device, etc.), because the network anomaly, downtime and other nodes can not guara

Label:In the case of a replica set deployment we add one or more quorum nodes, the quorum node is not used to back up the data, because it is responsible for the election of the main node, so the hardware is not too high requirements, you can deploy it on a separate server, the server can be a listener server, can also be deployed on the virtual machine, But a little bit. The

An arbiter (arbiter) is a MongoDB instance in a replication set that does not hold data. The quorum node uses minimal resources and does not require hardware devices, cannot deploy arbiter in one dataset node, can be deployed on other application servers or monitoring servers, or can be deployed in a separate virtual machine. To ensure that there are an odd number of voting members (including primary) in the replication set, the

An arbiter (arbiter) is a MongoDB instance in a replication set that does not hold data. The quorum node uses minimal resources and does not require hardware devices, cannot deploy arbiter in the same dataset node, can be deployed on other application servers or monitoring servers, or can be deployed in a separate virtual machine. To ensure that there are an odd number of voting members (including primary) in the replication set, the

Using shared folders to implement the quorum disk for a failover clusterIn the previous blog post we've introduced how to build a Distributed File System (DFS), and we've explained how to configure DFS to be highly available, so today's blog post We'll show you how to use DFS to make our Windows cluster arbitration disk.Don't know if you know me in front of the blog post Why do I want to be highly available for DFS configuration, in fact, I configure

Guide : JPMorgan's quorum platform is a hot spot in the block chain industry (Quorum is a block-chain network based on the Etheric square that JPMorgan first unveiled last autumn), and JPMorgan's recent contact with the 0-currency electronic currency Company (Zerocoin Electronic Coin Company) 's cooperation is the cause of hot discussion. Some experts say that the combination of 0 knowledge cryptography and

MongoDB's cluster approach is divided into three types of replica set/sharding/master-slaver, here only the simplest way to build a cluster (production environment), if there are multiple nodes can be and so on or view official documents.Replica SetChinese translation is called a replica set. In fact, the simple is that the cluster contains a number of data, to ensure that the main node hangs, the standby node can continue to provide data services, provided the premise is that the data needs and

1. Full Write 1 (write all, read one)Full Write 1 is the most intuitive copy control rule. When writing, only the copy is successful, only if it is written successfully. In this way, it is only necessary to read the data from one of the replicas to ensure correctness. This rule needs to solve a problem: if it is a KV system, if the first write of a key is only partially successful, then there is the result of the second write in the system, and the result of the first i-1. According to the rules

The previous article involves a lot of leader-related algorithms, we have the wood have thought, princely will phase, rather, since leader so troublesome, simply or use peer model bar, to a everyone equal structure. This article needs and everybody to discuss is the quorum mechanism that realizes the Democratic politics under the multi-copy. As to how it solves all the problems we mentioned earlier, we'll continue this article for a chat. 1. No-l

Recent projects need to establish cluster services for SQL Server, multiple SQL Server databases, and provide a unique URL access address. When the primary node loses power, the network is disconnected, the message is passed to the standby node through the heartbeat line, and the standby node takes over the database access task within 3 seconds to realize the dual-machine hot standby. Because the desktop is in place for 2 days, 2 sets of Windows Server R2 systems are installed on the virtual mac

.RECOVERING: Recovering, not applicable read 4.Arbiter: Arbitrator 5.Down: The node cannot reach 6.UNKNOWN: No other node state is acquired and it is not known what state, generally occurs in only two members of the architecture, brain fissure 7.Removed: Remove replication set 8.ROLLBACK: Data rollback, at the end of rollback, is transferred to recovering or secondary state 9. FATAL: Error.View Log grep "Replset FATAL" to find the wrong reason and redo Sync 10.PRIMARY: Master node 11. Secondary:

Good memory is inferior to bad blog, record, need to use directly later. This article configured the three MongoDB in the same machine, should be put three machines, but the resources are limited, a machine will be used, the configuration of a copy of the lumped ratio is not configured better. This article configures the use of the database version: 3.2.6 64-bit version 1, copy three points MongoDB to the server, the directory is: Mongo_master//192.168.1.11 27311 The main library is actually i

Recent projects need to set up a Cluster service for SQL Server, multiple SQL Server databases to set up cluster services, and provide a unique URL access address. When the primary node loses power and the network is disconnected, the message is passed to the standby node through the heartbeat line. The standby node takes over the database access task within 3 seconds. Realize the dual-machine hot standby. Because the desktop has been in place for 2 days. So the first 2 sets of Windows Server R2

server data in one replication set remains fully consistent. In a MongoDB replication Chi group, each server has the following states: Primary master node, one replica set and only one server is in the Primary state, only the master node can provide read and write services to the outside. If the primary node is hung, the replica sets will vote for a standby node to become the new master node. Secondary the standby node, the replica set allows for multiple secondary, and the da

Tags: error tip div Strong border Ora text requires round read-only routingTags: mssql/node and shared folder most OverviewPrior to the majority of node quorum configuration, most nodes generally 3 nodes above the odd number of nodes; The common use of 3 node nodes is a waste because AlwaysOn read-only routing can only take advantage of a read replica, However, starting from Windows2008, you can use a shared folder instead of a node to act as a

The quorum-based voting for replica control is due to [giifford, 1979] [2]. Each copy of a replicated data item is assigned a vote. Each operation then has to obtainRead Quorum(VR) orWrite Quorum(VW) to read or write a data item, respectively. If a given data item has a total of V votes, the quorums have to obey the following rules: VR + vw> V VW> V/2 Th