diff --git a/src/background/config.js b/src/background/config.js
index d676305..0cb3b31 100644
--- a/src/background/config.js
+++ b/src/background/config.js
@@ -27,7 +27,7 @@ let config = {
 	sphinx: {
 		host     : '127.0.0.1',
 		port     : 9306,
-		connectionLimit: 30
+		connectionLimit: 12
 	},
 
 	spider: {
diff --git a/tests/sphinx.test.js b/tests/sphinx.test.js
index f13013f..dfd2cf8 100644
--- a/tests/sphinx.test.js
+++ b/tests/sphinx.test.js
@@ -2,6 +2,7 @@ import { expect } from "chai";
 
 const mysql = require('mysql')
 const config = require('../src/background/config')
+const {pool} = require('../src/background/mysql')
 
 describe("sphinx", () => {
 	let sphinx;
@@ -58,4 +59,16 @@ describe("sphinx", () => {
 			done()
 		})
 	})
+
+	it("query limit",  function(done) {
+		const sphinx = pool()
+		let promises = []
+		sphinx.query(`delete from feed where id >= 0`, () => {
+			for(let i = 0; i < 500; i++)
+				promises.push(sphinx.query(`insert into feed(id, data) values(${i}, 'a')`))
+			Promise.all(promises).then(() => {
+				sphinx.query(`delete from feed where id >= 0`, () => done())	
+			})
+		})
+	})
 });