Question

我使用AWS EMR创建了一个presto集群。我正在使用所有默认配置。我想在主节点上编写一个python脚本，将查询推送到presto并获得结果。

我找到了PyHive库，但我不知道要在连接字符串中放入什么：

from pyhive import presto  # or import hive
cursor = presto.connect('localhost').cursor()
statement = 'SELECT * FROM my_awesome_data LIMIT 10'
cursor.execute(statement)
my_results = cursor.fetchall()

我认为localhost可能是正确的，因为我在presto集群的主节点上运行脚本，但是我收到了错误：

OperationalError: Unexpected status code 404
b'<!DOCTYPE html><html><head><title>Apache Tomcat/8.0.45 - Error report</title><style type="text/css">H1 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:22px;} H2 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:16px;} H3 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:14px;} BODY {font-family:Tahoma,Arial,sans-serif;color:black;background-color:white;} B {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;} P {font-family:Tahoma,Arial,sans-serif;background:white;color:black;font-size:12px;}A {color : black;}A.name {color : black;}.line {height: 1px; background-color: #525D76; border: none;}</style> </head><body><h1>HTTP Status 404 - /v1/statement</h1><div class="line"></div><p><b>type</b> Status report</p><p><b>message</b> <u>/v1/statement</u></p><p><b>description</b> <u>The requested resource is not available.</u></p><hr class="line"><h3>Apache Tomcat/8.0.45</h3></body></html>'

Answer 1

我发现EMR为Presto的网络连接器设置的端口是8889，所以连接正确：

from pyhive import presto
cursor = presto.connect(host='localhost', port=8889).cursor()
statement = 'SELECT * FROM my_awesome_data LIMIT 10'
cursor.execute(statement)
my_results = cursor.fetchall()

我得到了我的结果：

print(my_results)

[('tn', 44599263, 925636329.2440014), ('fp', 169984085, 3624296366.570987), ('fn', 6370, 488192.751), ('tp', 47909, 4036930.0270000002)]

Presto / Python：如何使用python连接到AWS EMR上的Presto？

1 个答案: