How can I use sqlwrite with backgroundPool?

5 次查看（过去 30 天）
Dave
Dave 2025-9-11
回答： Raymond Norris 2025-10-2
I am receiving real-time data and saving the data to a MS SQL Server database using sqlwrite with no problem. I want to run this on the backgroundPool to ensure the main thread remains responsive to user input. I have Parallel Computing Toolbox and a JDBC connection object that reads and writes to the MS SQL Server database with no issue.
However, when I create a parallel.pool.Constant object and pass it to parfeval, the connection object fails the check for a valid connection (~isopen(conn)) that is found in both sqlwrite (line 56) and fetch (line 69).
conn = database( ... );
bgConn = parallel.pool.Constant(conn);
f = parfeval(backgroundPool,@(c)isopen(c.Value),1,bgConn);
disp(['Bg Pool // ConnIsOpen: ' num2str(fetchOutputs(f))]);
returns
Bg Pool // ConnIsOpen: 0
If I try a function handle, I get a different error message.
fhConn = @()database( ... );
bgFhConn = parallel.pool.Constant(fhConn);
f = parfeval(backgroundPool,@(c)isopen(c.Value),1,bgFhConn);
disp(['Bg Pool // ConnIsOpen: ' num2str(fetchOutputs(f))]);
returns
One or more futures resulted in an error.
Caused by:
Error using parallel.pool.Constant/get.Value (line 188)
Unable to create parallel.pool.Constant on the workers.
Unable to resolve the name 'com.mathworks.jmi.ClassLoaderManager.getClassLoaderManager'.
How can I use parfeval to run sqlwrite? I see the same behaviour in both MATLAB 2024a and 2025a. Thanks for your help.

请先登录，再回答此问题。

回答（1 个）

Raymond Norris
Raymond Norris 2025-10-2
@Dave rather than creating the connection on the client side and passing it to each worker, take a look at createConnectionForPool - Initialize parallel pool using database connection - MATLAB. createConnectionForPool creates a connection for each worker in the pool.

类别

在 Help Center 和 File Exchange 中查找有关 Database Toolbox 的更多信息

标签

产品


版本

R2025a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by