You can configure the connection_limit and pool_timeout parameters while passing them in the connection string. You can set the connection_limit to 1 to make sure that prisma doesn't initiate new database connections, this way you won't get timeout errors.

Increasing the pool timeout would give the query engine more time to process queries in the queue.

Reference for connection_limit and pool_timeout parameters: Reference.

This is a common error when using a Prisma transaction with slightly heavy data. There is a default timeout for the Prisma transaction, but you can custom-set the timeout to suit your case, as shown below. The issue is happening because the time needed for the transaction is taking more time than the default time.

Update the transaction as follow:

    await this.prisma.$transaction(
  async (db) => {
    const caseFile = await this.findOneByLeadId(leadIdentifier);

    if (caseFile) {
      const { caseIdentifier } = caseFile;

      const update = { ...caseFile, notes };
      await db.case_file.update({
        where: { case_file_guid: caseIdentifier },
        data: {
          note_text: notes,
        },
      });

      await createNotesAction(db, caseIdentifier);
    } else {
      throw new Error("Case file not found");
    }
  },
  {
    maxWait: 5000, // 5 seconds max wait to connect to prisma
    timeout: 20000, // 20 seconds
  }
);