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Krunal BauskarPlease join Percona’s Senior Technical Manager, Alkin Tezuysal, and Percona’s Percona XtraDB Cluster Lead, Krunal Bauskar as they present their talk, Percona XtraDB Cluster: Failure Scenarios and their Recovery on Wednesday, January 30th, 2019, at 8:00 AM PST (UTC-8) / 11:00 AM EST (UTC-5). View the Recording Percona XtraDB Cluster (a.k.a PXC) is an open […]
On March 22, 2018, we held a webinar on how Percona XtraDB cluster 5.7 (PXC) and ProxySQL can help achieve your database clustering high availability needs. Firstly, thanks to all the attendees for taking time to attend the webinar and we are sure you had a webinar experience. We tried answering some of your high […]
In this blog post, we’ll look at how Percona XtraDB Cluster (PXC) executes FLUSH and LOCK handling. Introduction Percona XtraDB Cluster is a multi-master solution that allows parallel execution of the transactions on multiple nodes at the same point in time. Given this semantics, it is important to understand how Percona XtraDB Cluster executes statements regarding FLUSH […]
Please join Percona’s Ramesh Sivaraman (QA Engineer) and Krunal Bauskar (Software Engineer, Percona XtraDB Cluster Lead) as they present Percona XtraDB Cluster 5.7 with ProxySQL for Your MySQL High Availability and Clustering Needs on Thursday, March 22, 2018 at 8:30 am PDT (UTC-7) / 11:30 am EDT (UTC-4). Percona has developed Percona XtraDB Cluster (based […]
What if we tell you that there is a sure way to get IST not SST for node rejoins? You can guarantee that a new node rejoins using IST. Sound interesting? Keep reading. Normally when a node is taken out of the cluster for a short period of time (for maintenance or shutdown), gcache on other nodes of the cluster […]
In this blog, we will answer questions from our webinar on Percona XtraDB Cluster 101. Recently (7 Dec 2017) I presented a webinar about Percona XtraDB Cluster 101. Firstly, thanks to all the attendees: we had a great webinar with quite some interesting questions and feedback. Through this blog, I’ll answer most of the questions […]
In this blog post, we’ll look at how sequence numbers work in Percona XtraDB Cluster. Introduction Percona XtraDB Cluster uses multiple sequence numbers (seqno), each having a special role to play. Let’s try to understand the significance of each sequence number. global_seqno An active Percona XtraDB Cluster cluster has multiple write-sets (transactions) generated from one […]
Join Percona’s Software Engineer (PXC Lead), Krunal Bauskar as he presents Percona XtraDB Cluster 101 on Thursday, December 7, 2017, at 7:00 am PST / 10:00 am EST (UTC-8). Tags: Percona XtraDB Cluster, MySQL, High Availability, Clustering Experience Level: Beginner Percona XtraDB Cluster (PXC) is a multi-master solution that offers virtual synchronous replication among clustering […]
In a clustering environment, we often see a node that needs to be taken down for maintenance. For a node to rejoin, it should re-sync with the cluster state. In PXC (Percona XtraDB Cluster), there are 2 ways for the rejoining node to re-sync: State Snapshot Transfer (SST) and Incremental State Transfer (IST). SST involves […]
In this blog, we’ll look at how improvements to Percona XtraDB Cluster improved IST performance. Introduction Starting in version 5.7.17-29.20 of Percona XtraDB Cluster significantly improved performance. Depending on the workload, the increase in throughput is in the range of 3-10x. (More details here). These optimization fixes also helped improve IST (Incremental State Transfer) performance. This […]
In this blog, we’ll look at the differences in how a PREPARE statement handles errors in binary and text protocols. Introduction Since Percona XtraDB Cluster is a multi-master solution, when an application executes conflicting workloads one of the workloads gets rolled back with a DEADLOCK error. While the same holds true even if you fire […]
In this blog post, we’ll look at how we’ve improved wsrep-stages and related instrumentation in Percona XtraDB Cluster. Introduction When you execute a workload and need to find out what the given thread is working on, “SHOW PROCESSLIST” comes to the top of your mind. It is an effective way to track the thread status. We […]
In this blog post, we’ll look at a transaction replay anomaly in Percona XtraDB Cluster. Introduction Percona XtraDB Cluster/Galera replays a transaction if the data is non-conflicting but, the transaction happens to have conflicting locks. Anomaly Let’s understand this with an example: Let’s assume a two-node cluster (node-1 and node-2) Base table “t” is created […]
In this blog post, we’ll look at how increasing the fc_limit can affect SELECT latency. Introduction Recent Percona XtraDB Cluster optimizations have exposed fc_limit contention. It was always there, but was never exposed as the Commit Monitor contention was more significant. As it happens with any optimization, once we solve the bigger contention issues, smaller […]
In this blog post, we’ll look at how Percona XtraDB Cluster uses IST. Introduction Percona XtraDB Cluster uses the concept of an Incremental State Transfer (IST). When a node of the cluster leaves the cluster for a short period of time, it can rejoin the cluster by getting the delta set of missing changes from any active […]
In this blog post, we’ll discuss trackable flow control in Percona XtraDB Cluster. Introduction Percona XtraDB Cluster has a self-regulating mechanism called Flow Control. This mechanism helps to avoid a situation wherein the weakest/slowest member of the cluster falls significantly behind other members of the cluster. When a member of a cluster is slow at applying write-sets […]
In this blog post, we’ll look at the actions and efforts Percona experts took to scale Percona XtraDB Cluster. Introduction When we first started analyzing Percona XtraDB Cluster performance, it was pretty bad. We would see contention even with 16 threads. Performance was even worse with sync binlog=1, although the same pattern was observed even with […]
This post describes how to recover Galera Cache (or gcache) on restart. Recently Codership introduced (with Galera 3.19) a very important and long awaited feature. Now users can recover Galera cache on restart. Need If you gracefully shutdown cluster nodes one after another, with some lag time between nodes, then the last node to shutdown holds […]
In this blog I will provide answers to the questions and queries that some of you have raised during the webinar on Nov 17th. I would like to say thank you to all of the audience who attended the talk on November 17, 2016. You can also check the recording and slides here. Q. How is […]
This blog discusses some important aspects of GCache. Why do we need GCache? Percona XtraDB Cluster is a multi-master topology, where a transaction executed on one node is replicated on another node(s) of the cluster. This transaction is then copied over from the group channel to Galera-Cache followed by apply action. The cache can be discarded immediately […]