Expert insights. Personalized for you.
Database Availability Group (DAG) is a built-in framework in Microsoft Exchange Server that uses continuous replication and failover clustering to ensure high availability and site resilience. In Exchange Server, DAG refers to a cluster of Exchange Servers (up to 16 Exchange Mailbox Servers) that hosts a set of database copies and provides protection against switchover and failover. MORE
In this article, we will take a glance at the fundamentals of SQL Server statistics and discover their interaction with the query processing steps with simple examples. MORE
If you run several web servers in your organization or even public web servers on the internet, you need some kind of monitoring. If your servers go down for some reason, this may not be funny for your colleagues, customer, and even for yourself. Introduction. MORE
This article gives you an insight into SQL Server Index properties in SSMS. Introduction We can create indexes in SQL Server using both GUI and t-SQL method. Development Indexes SQL Server Management Studio (SSMS MORE
In this article, we will proceed with configuring a SQL Server Always On Availability Groups and perform failover validations. A comprehensive guide to SQL Server Always On Availability Groups on Windows Server 2016 Configuration of virtual machines on Oracle […]. MORE
This article explains SQL Server Dedicated Administrator Connections and how you can use it for Azure SQL Database. To begin an investigation, you try to connect the SQL Server using SQL Server Management Studio. MORE
In this article, we will explore Microsoft SQL Server trace flags with all aspects, and we will learn also how to use them. Introduction Trace flags are the advanced configuration options that are used to change specific behaviors of the SQL Server. MORE
SQL Server for Linux Performance Monitoring Improvements Last year I posted a blog with examples using Performance Co-Pilot, [link] , to monitor SQL Server on Linux. MORE
HOW IT WORKS: SQL Server Scheduler Affinity SQL Server uses 3 types of affinity to control where the SQL Server worker threads execute. Node Types SQL Server makes a specific distinction between scheduling and memory nodes. SQL Server may choose to divide the memory node allow ing for better partitioning and performance. This allows you to scale up or down the SQL Server schedulers without restarting the SQL Server. MORE
Introduction In this article, I’m going to explain what the Execution Plans in SQL Server are and how to understand the details of an execution plan by reading the various metrics available once we hover over the components in the plan. Execution plans SQL Server Management Studio (SSMS MORE
This article explores the Hybrid Buffer Pool feature available in the SQL Server 2019. Introduction SQL Server uses Dynamic Random Access Memory (D-RAM) buffer pool for caching data pages retrieved from the disk. Buffer Pool Extension (BPE) Execution plans Performance SQL Server 2019 MORE
In this article, we will talk about the query tuning features that were announced with SQL Server 2019. Performance SQL Server 2019Introduction Sometimes, tuning the queries can be a tough task for database developers or administrators. MORE
SQL Server Books Online documents Instant File Initialization and the associated security considerations. SQL Server performs the following API calls when creating or extending (growing) data and log files. If the file is a log file (LDF) SQL Server always writes a known pattern (other than zeros) to the allocated space. Trace flag: 1805 ( undocumented in SQL Server Books Online ): Disables instant file initialization for data files. MORE
SQL Server BDC Hints and Tips: TEMPDB Disk Usage I was troubleshooting a master-0 pod eviction due to disk pressure. Looking at the disk metrics I was able to map the time of the disk space increase to the startup of SQL Server, specifically TEMPDB. SQL Server BDC Hints and Tips BDC k8s tempdb MORE
SQL Server relies on Forced-Unit-Access (Fua) I/O subsystem capabilities to provide data durability, detailed in the following documents: SQL Server 2000 I/O Basic and SQL Server I/O Basics, Chapter 2. Durability is a cornerstone of any database system and starting with SQL Server 2017 on Linux Cumulative Update 6 (CU6), SQL Server on Linux enables “Forced Flush” behavior as described in this article , improving durability on non-Fua optimized systems. “Be MORE
I was asked to validate the SQL Server behavior in light of the error condition involving fsync/fdatasync outlined in this article. SQL Server does NOT do this, in fact I made sure SQL Server on Linux does not allow this to occur. This issue does NOT impact SQL Server database, log and backup files. SQL Server opens these file types using O_DIRECT to bypass file system cache. Bob Dorr – Principal Software Engineer SQL Server. MORE
The SQL Server Host Extension provides file level integrity. Bob Dorr – Principal Software Engineer SQL Server. SQL Server 2017 How It Works SQL Server on LinuxWhen Creating, Renaming or Deleting (remove/unlinking) a file, Linux requires the direct parent directory to be synchronized. As documented in the manpage for fsync core changes to the directory require the directory itself to be synchronized. MORE
SQL Server 2017 introduced a small change to SQL Server’s default worker thread calculation, accounting for smaller environments. When running on smaller environments SQL Server reduces the worker target. For an X64 installation, using the sp_configure ‘max worker threads’ value of 0 SQL Server uses the following calculation. On small environments SQL Server always uses 256 as the target. SQL Server 2017 MORE
Failures occur from remote clients or sqlcmd executed directory on the server (/opt/mssql-tools/bin). SQL Server 2017 CU10 does not show behavior. · SQL Server 2017 CU12 exhibits the behavior. Server is a Superdome with lots of CPUs and RAM. One of the first stops in debugging this issue is the SQL Server health session traces located in the /var/opt/mssql/log/system_health*.xel sp_server_diagnostics_component_result. MORE
However, discarding a server like this is expensive and inefficient. In this blog post, we will explain an approach to detect and fix transactions on the crashed MySQL master server in a semisynchronous replication setup, and how to re-slave it back into your master-slave setup. Re-Slaving a Crashed #MySQL Master Server in Semisynchronous Replication Setup Click To Tweet. Remember that you need to retain the UUID of this server as before. In a MySQL 5.7 MORE
SQL Server 2017 leverages up to 4 log writer workers, on hidden schedulers, to assist in transaction log processing activities. You may find the number of log write workers has been increased to 8 when running newer releases of SQL Server to accommodate larger systems. During SQL Server startup the number of log writer workers is determined. SQL Server 2017 General How It Works It Just Runs Faster NUMA Performance Scheduler MORE
The post Bad Habits: Avoiding NULL in SQL Server appeared first on SQLPerformance.com. A long time ago, I answered a question about NULL on Stack Exchange entitled, “ Why shouldn’t we allow NULLs? ” MORE
The partitioned memory and latch objects protect in-memory structures for short durations and can be sized according to available memory for SQL Server. Bob Dorr – Principal Software Engineer SQL Server Previous posts have discussed partitioning, for example, a partitioned memory object [link] and how a latch maintains the desired access (exclusive, shared, …) [link]. Quick Refresher Over Partitioned Protection/Locking. MORE
It is the 30th article in the SQL Server Always On Availability Groups series and explores column-level SQL Server encryption with AG groups. Always On Availability Groups Security SQL Server 2019 MORE
When starting SQL Server on Linux why are there two (2) sqlservr processes? systemctl status mssql-server mssql-server.service – Microsoft SQL Server Database Engine … CGroup: /system.slice/mssql-server.service ??85829 For those signals that default to capturing a full process CORE DUMP, SQL Server on Linux installs alternate signal handlers. Bob Dorr – Principle SQL Server Software Engineer. Linux SQL Server 2017 SQL Server on Linux MORE
When I joined Microsoft in 1993, I would embark on a 25 year journey working only on Windows laptops and Windows Server computers. Last October we released SQL Server 2017 including support for Linux and Docker Containers. Since then, I have spent a great deal of my time talking to customers directly and at events about SQL Server on Linux. So here in this blog post, I will show you my journey in taking the SQL Server Mac Challenge. Take the SQL Server Mac Challenge! MORE
In this article, we will explore a new SQL Server 2019 feature which is Scalar UDF (scalar user-defined) inlining. Development Functions Performance SQL Server 2019 MORE
In a MySQL master-slave high availability (HA) setup, it is important to continuously monitor the health of the master and slave servers so you can detect potential issues and take corrective actions. MySQL Master Server Health Checks. In this blog post, we explain some basic health checks you can do on your MySQL master and slave nodes to ensure your setup is healthy. MORE
How It Works: SQL Server Stack Trace – COMDAT Elimination Starting with SQL Server 2019, SQL Server is built with the COMDAT, ICF linker option enabled, reducing size/space usage. Caution: When symbolizing SQL server stack traces keep COMDAT elimination in mind when evaluating the validity of the stack. MORE
Following on my previous article. Run your own Video Conference Service with Jitsi , I started looking for a reliable solution to monitor my instance that runs Jitsi. I needed basic information on RAM, CPU, Disk, Networking, and I/O to assess the performance bottleneck for the serve. MORE
This article aims to provide some beneficial tips about SQL Server extended events that make it easier to create and use event sessions. Introduction SQL Server extended events is a performance monitoring tool that has the ability to collect various event data of the SQL Server. MORE
In this article, we will go through the details of the trivial execution plans and we will also tackle some examples about the trivial plans to explore effects on query performance. MORE
In this article, we will go through some details about SQL Server statistics. The first step into SQL Server statistics The query plan is a set of instructions that describes how a query will be executed by the database engine. MORE
Server page faults/second. database performance garbage collection memory leaks app server performance monioringBelow are some of the key metrics that need to be monitored during performance testing: CPU utilization. Heap memory utilization. Number of active/daemon threads. Number of classes loaded. Cache hit ratio. Active total sessions. SSL transactions/second. Active/total DB pool connections. Application log. Load balancing. Requests/second. MORE
In this article, we will learn how to monitor SQL Server blocking issues with different methods. How does a blocking occur in SQL Server? SQL Server uses the lock mechanism to protect […]. MORE
I have been making the same recommendations about tempdb since I started working with SQL Server over 15 years ago, when I was working with customers running version 2000. From the customer side, this has been the limit of what can be done*, until SQL Server 2019. The SQL Server team has made many changes over the years to try and mitigate issues, but the abuse continues. I have SQL Server 2019 CTP 3.2 MORE
Rethinking Server-Timing As A Critical Monitoring Tool. Rethinking Server-Timing As A Critical Monitoring Tool. In the world of HTTP Headers, there is one header that I believe deserves more air-time and that is the Server-Timing header. Setting Server-Timing. MORE
React Server Components aim to enable modern UX with a server-driven mental model. In this post I will share some notes I took while catching up on the latest RFC and talk around this work MORE
SQL Server dbcc clonedatabase - Gotcha The dbcc clonedatabase is a handy command to clone metadata and information such as query disk store. I have been testing SQL Server High Availability failovers in combination with database creates and drops, including clonedatabase. MORE
MySQL Server generates several logs that can help you monitor the activities of the server. Setting Up MySQL Server Logging. Managing MySQL Server Logs: Rotate, Compress, Retain & Delete Click To Tweet. Check out these other posts to learn more about optimizing your MySQL deployments: Calculating InnoDB Buffer Pool Size for your MySQL Server. MySQL Tutorial – Configuring and Managing SSL On Your MySQL Server. MORE
In a MySQL master-slave high availability (HA) setup, it is important to continuously monitor the health of the master and slave servers so you can detect potential issues and take corrective actions. MySQL Master Server Health Checks. Assuming that the monitoring script is running on the same server as your MySQL server, you can check for the following: Ensure the MySQL service is running. Important Health Checks for your MySQL Master-Slave Servers Click To Tweet. MORE
MySQL does not limit the number of slaves that you can connect to the master server in a replication topology. A classic solution for this problem is to deploy a binlog server – an intermediate proxy server that sits between the master and its slaves. MORE
This article explores the Causality tracking option in the SQL Server Extended Events session(XEvents) and its usefulness in troubleshooting performance issues. MORE
This article intends to give information about the SQL Server filtered indexes and their performance impacts. Introduction Indexes are the special data structures that help to improve the performance of the queries in SQL Server. MORE
Servers Related Topics Scalegrid
MAY 22, 2020
MySQL does not limit the number of slaves that you can connect to the master server in a replication topology. A classic solution for this problem is to deploy a binlog server – an intermediate proxy server that sits between the master and its slaves.
Scalegrid
FEBRUARY 17, 2020
In a MySQL master-slave high availability (HA) setup, it is important to continuously monitor the health of the master and slave servers so you can detect potential issues and take corrective actions. MySQL Master Server Health Checks. Assuming that the monitoring script is running on the same server as your MySQL server, you can check for the following: Ensure the MySQL service is running. Important Health Checks for your MySQL Master-Slave Servers Click To Tweet.
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DZone
OCTOBER 26, 2021
Database Availability Group (DAG) is a built-in framework in Microsoft Exchange Server that uses continuous replication and failover clustering to ensure high availability and site resilience. In Exchange Server, DAG refers to a cluster of Exchange Servers (up to 16 Exchange Mailbox Servers) that hosts a set of database copies and provides protection against switchover and failover.
Scalegrid
MAY 13, 2019
MySQL Server generates several logs that can help you monitor the activities of the server. Setting Up MySQL Server Logging. Managing MySQL Server Logs: Rotate, Compress, Retain & Delete Click To Tweet. Check out these other posts to learn more about optimizing your MySQL deployments: Calculating InnoDB Buffer Pool Size for your MySQL Server. MySQL Tutorial – Configuring and Managing SSL On Your MySQL Server.
DZone
SEPTEMBER 29, 2021
If you run several web servers in your organization or even public web servers on the internet, you need some kind of monitoring. If your servers go down for some reason, this may not be funny for your colleagues, customer, and even for yourself. Introduction.
Addy Osmani
DECEMBER 21, 2020
React Server Components aim to enable modern UX with a server-driven mental model. In this post I will share some notes I took while catching up on the latest RFC and talk around this work
SQL Shack
NOVEMBER 23, 2021
This article explores the Hybrid Buffer Pool feature available in the SQL Server 2019. Introduction SQL Server uses Dynamic Random Access Memory (D-RAM) buffer pool for caching data pages retrieved from the disk. Buffer Pool Extension (BPE) Execution plans Performance SQL Server 2019
High Scalability
FEBRUARY 17, 2020
In a MySQL master-slave high availability (HA) setup, it is important to continuously monitor the health of the master and slave servers so you can detect potential issues and take corrective actions. MySQL Master Server Health Checks. In this blog post, we explain some basic health checks you can do on your MySQL master and slave nodes to ensure your setup is healthy.
DZone
DECEMBER 30, 2020
Server page faults/second. database performance garbage collection memory leaks app server performance monioringBelow are some of the key metrics that need to be monitored during performance testing: CPU utilization. Heap memory utilization. Number of active/daemon threads. Number of classes loaded. Cache hit ratio. Active total sessions. SSL transactions/second. Active/total DB pool connections. Application log. Load balancing. Requests/second.
SQL Shack
AUGUST 27, 2021
In this article, we will take a glance at the fundamentals of SQL Server statistics and discover their interaction with the query processing steps with simple examples.
SQL Server According to Bob
SEPTEMBER 9, 2019
The partitioned memory and latch objects protect in-memory structures for short durations and can be sized according to available memory for SQL Server. Bob Dorr – Principal Software Engineer SQL Server Previous posts have discussed partitioning, for example, a partitioned memory object [link] and how a latch maintains the desired access (exclusive, shared, …) [link]. Quick Refresher Over Partitioned Protection/Locking.
SQL Shack
NOVEMBER 17, 2021
This article aims to provide some beneficial tips about SQL Server extended events that make it easier to create and use event sessions. Introduction SQL Server extended events is a performance monitoring tool that has the ability to collect various event data of the SQL Server.
SQL Shack
SEPTEMBER 28, 2020
In this article, we will explore a new SQL Server 2019 feature which is Scalar UDF (scalar user-defined) inlining. Development Functions Performance SQL Server 2019
SQL Shack
OCTOBER 12, 2020
It is the 30th article in the SQL Server Always On Availability Groups series and explores column-level SQL Server encryption with AG groups. Always On Availability Groups Security SQL Server 2019
SQL Server According to Bob
FEBRUARY 11, 2019
SQL Server 2017 leverages up to 4 log writer workers, on hidden schedulers, to assist in transaction log processing activities. You may find the number of log write workers has been increased to 8 when running newer releases of SQL Server to accommodate larger systems. During SQL Server startup the number of log writer workers is determined. SQL Server 2017 General How It Works It Just Runs Faster NUMA Performance Scheduler
SQL Performance
OCTOBER 21, 2021
The post Bad Habits: Avoiding NULL in SQL Server appeared first on SQLPerformance.com. A long time ago, I answered a question about NULL on Stack Exchange entitled, “ Why shouldn’t we allow NULLs? ”
SQL Server According to Bob
APRIL 24, 2018
When I joined Microsoft in 1993, I would embark on a 25 year journey working only on Windows laptops and Windows Server computers. Last October we released SQL Server 2017 including support for Linux and Docker Containers. Since then, I have spent a great deal of my time talking to customers directly and at events about SQL Server on Linux. So here in this blog post, I will show you my journey in taking the SQL Server Mac Challenge. Take the SQL Server Mac Challenge!
DZone
APRIL 30, 2020
Following on my previous article. Run your own Video Conference Service with Jitsi , I started looking for a reliable solution to monitor my instance that runs Jitsi. I needed basic information on RAM, CPU, Disk, Networking, and I/O to assess the performance bottleneck for the serve.
SQL Performance
AUGUST 2, 2019
I have been making the same recommendations about tempdb since I started working with SQL Server over 15 years ago, when I was working with customers running version 2000. From the customer side, this has been the limit of what can be done*, until SQL Server 2019. The SQL Server team has made many changes over the years to try and mitigate issues, but the abuse continues. I have SQL Server 2019 CTP 3.2
SQL Server According to Bob
DECEMBER 18, 2018
The SQL Server Host Extension provides file level integrity. Bob Dorr – Principal Software Engineer SQL Server. SQL Server 2017 How It Works SQL Server on LinuxWhen Creating, Renaming or Deleting (remove/unlinking) a file, Linux requires the direct parent directory to be synchronized. As documented in the manpage for fsync core changes to the directory require the directory itself to be synchronized.
SQL Shack
JULY 15, 2020
In this article, we will proceed with configuring a SQL Server Always On Availability Groups and perform failover validations. A comprehensive guide to SQL Server Always On Availability Groups on Windows Server 2016 Configuration of virtual machines on Oracle […].
SQL Shack
OCTOBER 12, 2021
In this article, we will learn how to monitor SQL Server blocking issues with different methods. How does a blocking occur in SQL Server? SQL Server uses the lock mechanism to protect […].
SQL Server According to Bob
AUGUST 23, 2021
HOW IT WORKS: SQL Server Scheduler Affinity SQL Server uses 3 types of affinity to control where the SQL Server worker threads execute. Node Types SQL Server makes a specific distinction between scheduling and memory nodes. SQL Server may choose to divide the memory node allow ing for better partitioning and performance. This allows you to scale up or down the SQL Server schedulers without restarting the SQL Server.
SQL Server According to Bob
FEBRUARY 10, 2019
Failures occur from remote clients or sqlcmd executed directory on the server (/opt/mssql-tools/bin). SQL Server 2017 CU10 does not show behavior. · SQL Server 2017 CU12 exhibits the behavior. Server is a Superdome with lots of CPUs and RAM. One of the first stops in debugging this issue is the SQL Server health session traces located in the /var/opt/mssql/log/system_health*.xel sp_server_diagnostics_component_result.
SQL Shack
AUGUST 23, 2021
In this article, we will go through some details about SQL Server statistics. The first step into SQL Server statistics The query plan is a set of instructions that describes how a query will be executed by the database engine.
SQL Shack
NOVEMBER 23, 2020
In this article, we will talk about the query tuning features that were announced with SQL Server 2019. Performance SQL Server 2019Introduction Sometimes, tuning the queries can be a tough task for database developers or administrators.
Scalegrid
DECEMBER 9, 2019
However, discarding a server like this is expensive and inefficient. In this blog post, we will explain an approach to detect and fix transactions on the crashed MySQL master server in a semisynchronous replication setup, and how to re-slave it back into your master-slave setup. Re-Slaving a Crashed #MySQL Master Server in Semisynchronous Replication Setup Click To Tweet. Remember that you need to retain the UUID of this server as before. In a MySQL 5.7
SQL Shack
OCTOBER 14, 2021
This article explores the Causality tracking option in the SQL Server Extended Events session(XEvents) and its usefulness in troubleshooting performance issues.
SQL Shack
FEBRUARY 3, 2022
In this article, we will go through the details of the trivial execution plans and we will also tackle some examples about the trivial plans to explore effects on query performance.
Smashing Magazine
MAY 16, 2022
Rethinking Server-Timing As A Critical Monitoring Tool. Rethinking Server-Timing As A Critical Monitoring Tool. In the world of HTTP Headers, there is one header that I believe deserves more air-time and that is the Server-Timing header. Setting Server-Timing.
SQL Server According to Bob
FEBRUARY 10, 2019
SQL Server 2017 introduced a small change to SQL Server’s default worker thread calculation, accounting for smaller environments. When running on smaller environments SQL Server reduces the worker target. For an X64 installation, using the sp_configure ‘max worker threads’ value of 0 SQL Server uses the following calculation. On small environments SQL Server always uses 256 as the target. SQL Server 2017
SQL Shack
AUGUST 17, 2021
This article intends to give information about the SQL Server filtered indexes and their performance impacts. Introduction Indexes are the special data structures that help to improve the performance of the queries in SQL Server.
SQL Server According to Bob
MAY 21, 2020
SQL Server for Linux Performance Monitoring Improvements Last year I posted a blog with examples using Performance Co-Pilot, [link] , to monitor SQL Server on Linux.
SQL Server According to Bob
JULY 17, 2018
When starting SQL Server on Linux why are there two (2) sqlservr processes? systemctl status mssql-server mssql-server.service – Microsoft SQL Server Database Engine … CGroup: /system.slice/mssql-server.service ??85829 For those signals that default to capturing a full process CORE DUMP, SQL Server on Linux installs alternate signal handlers. Bob Dorr – Principle SQL Server Software Engineer. Linux SQL Server 2017 SQL Server on Linux
SQL Server According to Bob
FEBRUARY 7, 2020
SQL Server dbcc clonedatabase - Gotcha The dbcc clonedatabase is a handy command to clone metadata and information such as query disk store. I have been testing SQL Server High Availability failovers in combination with database creates and drops, including clonedatabase.
SQL Shack
APRIL 13, 2022
In this article, we will explore Microsoft SQL Server trace flags with all aspects, and we will learn also how to use them. Introduction Trace flags are the advanced configuration options that are used to change specific behaviors of the SQL Server.
SQL Server According to Bob
DECEMBER 9, 2021
How It Works: SQL Server Stack Trace – COMDAT Elimination Starting with SQL Server 2019, SQL Server is built with the COMDAT, ICF linker option enabled, reducing size/space usage. Caution: When symbolizing SQL server stack traces keep COMDAT elimination in mind when evaluating the validity of the stack.
SQL Shack
MARCH 29, 2022
This article explains SQL Server Dedicated Administrator Connections and how you can use it for Azure SQL Database. To begin an investigation, you try to connect the SQL Server using SQL Server Management Studio.
SQL Server According to Bob
DECEMBER 18, 2018
I was asked to validate the SQL Server behavior in light of the error condition involving fsync/fdatasync outlined in this article. SQL Server does NOT do this, in fact I made sure SQL Server on Linux does not allow this to occur. This issue does NOT impact SQL Server database, log and backup files. SQL Server opens these file types using O_DIRECT to bypass file system cache. Bob Dorr – Principal Software Engineer SQL Server.
SQL Shack
JULY 2, 2020
This article gives you an insight into SQL Server Index properties in SSMS. Introduction We can create indexes in SQL Server using both GUI and t-SQL method. Development Indexes SQL Server Management Studio (SSMS
SQL Shack
MARCH 10, 2020
Introduction In this article, I’m going to explain what the Execution Plans in SQL Server are and how to understand the details of an execution plan by reading the various metrics available once we hover over the components in the plan. Execution plans SQL Server Management Studio (SSMS
SQL Server According to Bob
DECEMBER 10, 2018
SQL Server Books Online documents Instant File Initialization and the associated security considerations. SQL Server performs the following API calls when creating or extending (growing) data and log files. If the file is a log file (LDF) SQL Server always writes a known pattern (other than zeros) to the allocated space. Trace flag: 1805 ( undocumented in SQL Server Books Online ): Disables instant file initialization for data files.
SQL Server According to Bob
JANUARY 17, 2020
SQL Server BDC Hints and Tips: TEMPDB Disk Usage I was troubleshooting a master-0 pod eviction due to disk pressure. Looking at the disk metrics I was able to map the time of the disk space increase to the startup of SQL Server, specifically TEMPDB. SQL Server BDC Hints and Tips BDC k8s tempdb
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