使用locust运行并发测试，只要我设置并发数超过1000+，用户达到1020个左右的时候就会出现连接错误，错误日志如下，求高手帮忙分析下是什么原因：
ConnectionError(MaxRetryError("HTTPConnectionPool(host='192.168.1.18', port=8100): Max retries exceeded with url: /api/check/getcheckinfolist?input=%20%7B%22pageIndex%22:1,%22pageSize%22:20,%22medRecNO%22:%22%22,%22accessionNumber%22:%22%22,%22visitID%22:%22%22,%22outPatientID%22:%22%22,%22alternateVisitID%22:%22%22,%22iDCardNo%22:%22%22,%22addressDetail%22:%22%22,%22patientName%22:%22%22,%22examStartTime%22:%222018-01-01%2000:00:00%22,%22examEndTime%22:%222018-07-01%2023:59:59%22,%22registerStartTime%22:%22%22,%22registerEndTime%22:%22%22,%22resultStartDate%22:%22%22,%22resultEndDate%22:%22%22,%22requestStartTime%22:%22%22,%22requestEndTime%22:%22%22,%22lastUpdateStartDate1%22:%22%22,%22lastUpdateEndDate1%22:%22%22,%22gender%22:%22%22,%22age%22:0,%22ageUnit%22:%22%E5%B2%81%22,%22birthDay%22:%22%22,%22patientClass%22:[],%22requestDeptID%22:[],%22requestDocName%22:%22%22,%22organizationID%22:[],%22serviceSectID%22:[],%22resultAssistantName%22:%22%22,%22examStatus%22:[],%22ifHasImage%22:%22%22,%22resultPrintCount%22:%22%22,%22criticalValue%22:%22%22,%22quicksearch%22:%22%22,%22UserInfo%22:%7B%22userUID%22:%22e7468084-46b3-4560-a64c-a9c200b1e3be%22,%22loginName%22:%22jm1%22,%22userName%22:%22%E8%B4%BE%E8%8B%97%22,%22workNO%22:%22004%22,%22officePhone%22:%22%22,%22privatePhone%22:%2215869525458%22,%22email%22:%2230919454@qq.com%22,%22isSuperManager%22:false,%22organizationID%22:%22local%22,%22organizationName%22:%22%E6%AD%A6%E6%B1%89%E4%B8%AD%E5%BF%83%E5%8C%BB%E9%99%A2%22,%22deptID%22:%22%22,%22deptName%22:null%7D%7D (Caused by NewConnectionError(': Failed to establish a new connection: [Errno 24] Too many open files'))"))
