Is it possible to set the Minimum number of connections and the Minimum number of Idle connections in PostgreSQL Using Golang?
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Java uses restful to connect to taosdb to insert data, and setting maxconnect=30 under the pool configuration item in taosadapter.toml does not take effect.
The maximum number of connections in a single connection pool is still 20, and the maxIdle configuration and idleTimeout configuration need to be enabled at the same time as the maxConnect configuration, otherwise an error will be reported when connecting: error "connect taosd error" model=restful sessionID=6 error=invalid capacity settings
Database parameters used: show databases
Verbs used: Insert/Import/Select?
Environment:
OS: [e.g. CentOS 7.0]
Memory, CPU, current Disk Space
TDengine Version [e.g. 1.6.1.7]
Based on these system scalar Functions:
##CONNECTIONS:This function returns the number of attempted connections - both successful and unsuccessful - since SQL Server was last started.
##MAX_CONNECTIONS: Returns the maximum number of simultaneous user connections allowed on an instance of SQL Server. The number returned is not necessarily the number currently configured, returns always 32767.
My Question is this: We know millions of users can connect to sql server at the same time why ##MAX_CONNECTIONS says that only 32767 users can connect to sql server at the same time.
Microsoft covered this topic describes how to set the user connections server configuration option in SQL Server 2017 by using SQL Server Management Studio or Transact-SQL.
The user connections option specifies the maximum number of simultaneous user connections that are allowed on an instance of SQL Server.
The actual number of user connections allowed also depends on the version of SQL Server that you are using, and also the limits of your application or applications and hardware. SQL Server allows a maximum of 32,767 user connections. Because user connections is a dynamic (self-configuring) option, SQL Server adjusts the maximum number of user connections automatically as needed, up to the maximum value allowable.
For example, if only 10 users are logged in, 10 user
connection objects are allocated. In most cases, you do not have to
change the value for this option. The default is 0, which means that
the maximum (32,767) user connections are allowed.
more description here
I wanted to understand what will be the impact of performance on server if i set Max Pool size =500 and Connection Lifetime=60 seconds in connection string specified in web.config
Is it dangerous to set connection max pool size as well as connection lifetime=60s ? I added this configuration as I was getting exception thrown for default connection max pool size i.e 200 so had to increase it to 500 though i am closing my connection properly as explained in other forums as well as Microsoft docs?
I am using version 2.3.7 for Java 6. I have set maximumPoolSize to 200 and connectionTimeout to 30 s. I run into SQLTimeoutExceptions from BaseHikariPool.getConnection in one of our load test cases involving 70 simultaneous users uploading 10 files each. I turned on debug logging and obtained pool stats. So it would seem that the pool isn't being exhausted. Rather, HikariCP takes longer than connectionTimeout to create new connections. How can I debug this part of the process? The underlying data source is SQLServerDataSource version 4.1.
connectionTimeout is the maximum time to wait for obtaining connection from pool.
it is NOT time out for creating connection from data source. there is none.
You may want to consider reducing pool size. begin load testing with minimum and gradually increasing till SqlServer begins to take much longer to create connection.
check about pool size
HTH
It might be because in HikariCP opening a connection is a blocking call (
https://github.com/brettwooldridge/HikariCP/issues/1287)
You might find this option useful com.zaxxer.hikari.blockUntilFilled. With this option connection pool will open minimumIdle connections in parallel during initialization instead of lazy initializing connections.
I was wondering if anyone knows how to set up connection pooling for Sitecore 6 running on SQLServer 2005 ?
And is this a good idea to setup on a Sitecore solution? Or probably more correct, will there be any problems if setup incorrectly?
Any other comments or tips about this are also greatly appreciated.
The answers from Sitecores support:
By default, connection pooling is
enabled in ADO.NET (it means that we
don't need any connection string
parameters to enable it, parameters
are needed only to disable or to tune
the connection pooling). Thats why
there are no connection pooling
parameters in the default connection
strings. For more information please
refer to the following MSDN articles:
http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.connectionstring.aspx
http://msdn.microsoft.com/en-us/library/8xx3tyca.aspx
If you wish to tune the Database
Connection Pooling, you can add
appropriate parameters to the
connection strings.
Second reply after I asked some more about it:
Please see
http://msdn.microsoft.com/en-us/library/8xx3tyca%28v=vs.80%29.aspx
When a connection is first opened, a
connection pool is created based on an
exact matching algorithm that
associates the pool with the
connection string in the connection.
If MinPoolSize is either not specified
in the connection string or is
specified as zero, the connections in
the pool will be closed after a period
of inactivity. However, if the
specified MinPoolSize is greater than
zero, the connection pool is not
destroyed until the AppDomain is
unloaded and the process ends.
Maintenance of inactive or empty pools
involves minimal system overhead.
Following connection strings
parameters can be applied.
# Max Pool Size - specifies the
maximum size of your connection pool.
Default is 100. Most Web sites do not
use more than 40 connections under the
heaviest load but it depends on how
long your database operations take to
complete. # Min Pool Size - initial
number of connections that will be
added to the pool upon its creation.
Default is zero; however, you may
chose to set this to a small number
such as 5 if your application needs
consistent response times even after
it was idle for hours. In this case
the first user requests won't have to
wait for those database connections to
establish. # Pooling - controls if
your connection pooling on or off.
Default as you may've guessed is true.
I hope this helps others.
The only mentioning about negative impacts I'm aware about is this.