Questions tagged [connection-pooling]

In client applications, a connection pool is a cache of connections maintained so that the connections can be reused when future requests to the resource are required. Many DBMSes also support server-side connection-pooling allowing them to service more concurrent clients than they have server-side processes or threads servicing them.

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21
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2answers
33k views

Connection pools being reset with Error: 18056, Severity: 20, State: 46. & Perfmon Counters not showing

We are using SQL Authentication (to reduce the number of connection pools) & .NET 4.0 connection strings to connect to SQL Server Enterprise Edition 2012 SP1 on a Windows 2008 R2 Enterprise Server:...
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3answers
2k views

“When a connection is closed and returned to the pool, the isolation level from the last SET TRANSACTION ISOLATION LEVEL statement is retained”?

The MSDN online article "Snapshot Isolation in SQL Server" states: "An isolation level has connection-wide scope, and once set for a connection with the SET TRANSACTION ISOLATION LEVEL statement, it ...
9
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1answer
7k views

Choice of connection pooling library for VM deploys

HickariCP docs say: HikariCP relies heavily on accurate high-resolution timers for both performance and reliability. It is imperative that your server is synchronized with a time-source such as ...
9
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1answer
6k views

What is the purpose of session pool_mode in pgbouncer?

Since in this mode pgbouncer creates outbound connection for each inbound connection it seems to me that pgbouncer doesn't work as pooler. It's just 1 to 1 mapping. Where am I wrong?
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2answers
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Feasible to have thousands of users in Postgres?

We are creating SAAS where we will at most have 50.000 customers. We are considering creating a user in the Postgres database for each customer. We will map each user that logs into our service to a ...
9
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2answers
2k views

Postgres with pgpool architecture

Below is an example pgpool architecture: This implies that you only need to have pgpool on a single server; is this true? When I look at the configuration I also see that you configure backends ...
8
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3answers
2k views

How to understand the PostgreSQL discrepancy between connection pool recommendation ((2 * n_cores) + n_disks) and support for 100s of connections?

From PostgreSQL docs: Number of Database Connections -> How to Find the Optimal Database Connection Pool Size for optimal throughput the number of active connections should be somewhere near ((...
7
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2answers
2k views

Verifying connection pooling server side with CONTEXT_INFO on

I'm working with a 3 tiered application, Microsoft Dynamics AX, where the middle tier maintains connections to a SQL Server. Several clients connect to this middle tier server. The middle tier server ...
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3answers
10k views

Downside of large “max connections” in a connection pool from a web app [closed]

I understand that if you don't pool database connections at all, then you bear the overhead of establishing a new database connection every time you need to query the database, which will make your ...
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1answer
1k views

SQL Connection Pooling

I have a .net website connecting to SQL. Just wondering if connection pooling is enabled by default or is it something I have to activate myself?
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3answers
8k views

How to handle MySQL database connections/pooling from Lambda -> RDS with Node

I'm running into some problems while testing my Lambda function. I my test, I execute in parallel N executions of my Lambda function. In my lambda function, I retrieve a database connection through ...
5
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2answers
3k views

How to handle connection pooling for massive multi-tenancy/multi-schema environment

Here's a quick run down of the situation: We have 1 Schema per customer. We have 2000+ customers. We have 50+ Database servers (with the above schema's distributed unevenly amongst them). We are ...
4
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1answer
739 views

Are database connections from an application expensive from a performance point of view?

A colleague tells me that connections to a database are expensive and could harm performance of the application. They ask me to create a procedure that calls say another 8 procedures, that way they ...
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2answers
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Shared connection pool in SQL Server and prevention of cross-database queries

Microsoft recommends that a shared connection pool should be used when running e.g. a SaaS software with one database per customer but with a shared codebase to prevent pool fragmentation: https://...
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2answers
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Mysql Connection Pooling Similar To PostgreSQL's PgBouncer

I'm looking for a pooling solution for mysql that is independent of the language. I am using PGBouncer as an example because it Resides on the server the database is on Just change the connection ...
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2answers
110 views

Edit Application Name to Log Connection once for Logons on Pooled Connections

I am wondering if I can change the application name of a connection in SQL Server itself, e.g. in the logon trigger? Is that possible or is the application name "read only"? Edit to explain the ...
3
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2answers
618 views

Sql server sleeping state is increasing using ADO.NET?

We have one live ASP.Net application which is used by around 1000 concurrent users. In this application we have used connection pooling. There are 2 connection string defined in web.config with ...
3
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1answer
370 views

Confused about maximum connections in PostgreSQL

I am building a web application and I using PostgreSQL as the database management system. The following page details the maximum connections setting: https://www.postgresql.org/docs/9.5/static/...
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1answer
292 views

Does missing logout event in SQL Server trace mean connection leak?

(originally asked this question on StackOverflow was told that this community is a right one). I am investigating possibility of unreleased SQL Server database connections. I ran SQL Server Profiler ...
3
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1answer
267 views

Error creating connection pool for dbid:

We have an application that uses TomCat and Java to receive files and move them to a SQL Server 2012 instance. Previous versions of this software worked just fine. The new release fails on our ...
3
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1answer
2k views

Connection Timeouts and Failed Database Connections on AWS RDS

Environment details - Amazon RDS running PostgreSQL 9.3.14, db.r3.xlarge, IOPS 2000, 500 GB Issue - Numerous java.sql.SQLTimeoutException: Timeout after 30000ms of waiting for a connection and java....
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1answer
30k views

JDBC pooling Oracle driver Socket read timed out [duplicate]

I run Java EE application on Glassfish server v3 together with Oracle 12 DB on the same machine under Windows Server 2012 64bit. I use latest ojdbc7 driver. Connection pool config: <jdbc-...
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1answer
1k views

Connection pool Error

I am getting the below error from my .net application. Source: xxx.Services.xxx.xxx.xxxx.xxxx.xxxxRequest --- System.Data.Entity.Core.EntityException: The underlying provider failed on Open. -...
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2answers
173 views

Connection pooling - NodeJS or Database products?

Consider the mysql package. The description covers connection pooling thus, Rather than creating and managing connections one-by-one, this module also provides built-in connection pooling using ...
2
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1answer
170 views

When should I start using connection pooling?

I have a MySQL database that peaks at about 300 connections/sec. What is the recommended connections per server and at what point should I start using connection pooling?
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1answer
1k views

What is the sense to use server_lifetime with PgBouncer?

I've found server_lifetime option in PgBouncer config, and I'm trying to undestand if it is really needed in our case. https://pgbouncer.github.io/config.html The pooler will try to close server ...
2
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1answer
4k views

High Number of Connections

The below query tells me there is a total of 520 connections to our SQL Server database. Status of all is 'sleeping' except for 4 connections. The login_time goes back to 2 days ago on some ...
2
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1answer
564 views

MongoDB Connection Issues

We have a MEAN application with a 3-member MongoDB replica set. Somehow the total connection count keeps increasing until the primary is not able to take any new connections and goes down, making the ...
2
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1answer
1k views

Hundreds of TCP connections opened by sqlservr.exe

We have Tomcat on one machine and SQL Server on another. Our SQL Server machine is Windows 2008 R2 64bit machine with 32GB usable RAM 4 processors, 16 cpus. We use database pooling to keep db ...
2
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1answer
536 views

Sleeping connections

I have a dedicated MySQL server(8GB) with following configuration. [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock user=mysql lower_case_table_names = 1 default-storage-engine=...
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0answers
44 views

Database connections and related issues?

If my tomcat is configured to accept 100 incoming requests concurrently, how many connections should be present in DB connection pool ? In other words, if there a known optimal ratio of number of ...
2
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0answers
217 views

Connection Pools and TempDB Internal Objects

I am thinking I know the basics of the problem here, but I want to make sure I know the details before trying to explain it to others. We recently upgraded our third party application software to a ...
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2answers
283 views

SSMS How do I open a new Query Window using Same Connection Instance of current Window

Coming from Oracle I have discovered that SSMS connects slightly different than Oracle's SQL Developer. Oracle you click ONE connection and then all tabs you open then use that Connection. SSMS ...
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1answer
552 views

Is it possible to configure pgbouncer to distribute queries among master and slave?

We have master (write-read) and slave (readonly) Postgres 10 databases. Slave is online replication from master. Now our application (c# webapi) connects to master only directly. We want to execute ...
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1answer
8k views

Tomcat7 JDBC connection pool -> Connection has been abandoned

I have the following configuration for the JDBC connection pool initialSize="2" minIdle="10" maxIdle="50" maxActive="100" maxWait="15000" jdbcInterceptors="org.apache.tomcat.jdbc.pool.interceptor....
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1answer
266 views

How many pool connection size should be set for a 1000 users Jira system?

For a Jira system, if use Jira's default connection configuration as below: <?xml version="1.0" encoding="UTF-8"?> <jira-database-config> <name>defaultDS</name> <...
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1answer
604 views

Debug Connection Pool Error

I have been getting the below error. System.Data.Entity.Core.EntityException: The underlying provider failed on Open. ---> System.InvalidOperationException: Timeout expired. The timeout ...
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1answer
3k views

Python Postgres psycopg2 ThreadedConnectionPool exhausted

I have looked into several 'too many clients' related topic here but still can't solve my problem, so I have to ask this again, for me specific case. Basically, I set up my local Postgres server and ...
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2answers
322 views

How to Deal with Performace counters

Recently we got this alert from monitoring team. SQLServer:General Statistics Logins/sec has exceeded the threshold of 2 I tried to know a bit about it and if the value is less than 2 per ...
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1answer
648 views

Mysql connection pool set timezone

Service application is nodejs It is using mysql connection pool. Currently, we will plan to sell service to another country What is the best way to set timezone? timezone setting execute, and query ...
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1answer
436 views

Grouping SQL Server Connections By Connection Pool

In SQL Server 2014 is there a way to group connections by the connection pool that belong to? We are trying to find out if a specific application is leaking connections and hitting the default max ...
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2answers
10k views

Connection problem different errors .net application

We have a SQL Server with some relational databases. We have another webserver with applications which communicate with the databases. We have an issue with one of our customers. We get some errors ...
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1answer
3k views

ORA-12516 but max_utilization not reaching limit

Our app began to raise ORA-12516, TNS:listener could not find available handler with matching protocol stack errors, and I'm trying to diagnose why. The workload has not changed, so I think we might ...
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0answers
22 views

how to maximize usage of number of databases on a postgres server while limited by connections

We're building a system where ideally we'd give a database per client in a multi-tenant setup. However, although a single Postgres install supports 4,294,950,911 databases on a server, the suggested ...
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0answers
63 views

concurrent configuration PostgreSQL and tomcat

Postgresql has a default of 100 regarding max_connections. Tomcat pooling has a default of 100 regarding maxActive and maxIdle. How about configuring data sources in context.xml for Apps in Tomcat? ...
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0answers
5k views

org.postgresql.util.PSQLException: This connection has been closed. error for long running transactions

We are getting "org.postgresql.util.PSQLException: This connection has been closed." on one of our deployments for only long running transactions (more than a few minutes): Caused by: org.hibernate....
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0answers
651 views

Keeping MySql connections alive

I'm running a Windows service, which connects to a MySql database via Entity Framework. Every 10 seconds it issues a query to the database to see if any new records have been added. If it finds any, ...
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1answer
535 views

Periodic connection failure on SQL Server 2012 AlwaysOn cluster

Since last wednesday (so a we're dealing with this for a week now) we're getting periodic connection problems on our production database cluster. (An alwayson cluster running on windows 2012, three ...
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0answers
1k views

Check Postgres Listener is up/down?

I am using PostgreSQL LISTEN/NOTIFY functionality in Java. So I have made a ListenerBean which is run at Application startup. LISTENER class in java: @Singleton @Startup ...
0
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1answer
122 views

how to find a connection string value for a session in sql server?

I know there was a similar question before at SO as shown here However, that answer really does not address my question. So here is my scenario, and I will demo it with PowerShell. The following code ...