示例：从 ArcGIS Server 日志中获取地图服务统计数据

本 ArcGIS REST API 示例显示了如何对 ArcGIS Server 日志进行信息挖掘以获取各服务的统计数据。下面的脚本读取了过去 24 小时内与所完成的地图绘制有关的所有日志消息，并持续追踪 24 小时内所绘制的服务和绘制耗时。然后，写入一个以逗号分隔的文本文件，此文件汇总了绘制的次数以及每个服务的平均绘制时间。

要尝试本示例，请执行以下步骤：

1. 发布若干地图服务（无需定义切片缓存）。
2. 将 ArcGIS Server 日志级别设置为精细 (FINE)。
3. 通过将这些服务添加到 ArcMap 或在 ArcGIS Server 管理器中单击这些服务的缩略图并缩放和平移以发出这些服务的绘制请求。
4. 运行此脚本并检查所生成的文本文件。也可以使用 .csv 扩展名重命名此文件，并在 Microsoft Excel 等电子表格程序中打开。

# Queries the logs and writes statistics on map service activity during the past 24 hours

# For Http calls
import httplib, urllib, json

# For system tools
import sys, time

# For reading passwords without echoing
import getpass

#Defines the entry point into the script
def main(argv=None):
    # Print some info
    print
    print "This tool is a sample script that queries the ArcGIS Server logs and writes a report"
    print "  summarizing all map service draws within the past 24 hours."
    print
    
    # Ask for admin/publisher user name and password
    username = raw_input("Enter user name: ")
    password = getpass.getpass("Enter password: ")
 
    
    # Ask for server name
    serverName = raw_input("Enter Server name: ")
    serverPort = 6080

    # Ask for text file path
    filePath = raw_input("Enter the path of the text file where the statistics should be written.")

    millisecondsToQuery = 86400000 # One day 
    hitDict = {}
    
    # Get a token
    token = getToken(username, password, serverName, serverPort)
    if token == "":
        print "Could not generate a token with the username and password provided."
        return
    
    # Construct URL to query the logs
    logQueryURL = "/arcgis/admin/logs/query"
    startTime = int(round(time.time() * 1000))
    endTime = startTime - millisecondsToQuery
    logFilter = "{'services':'*','server':'*','machines':'*'}"
    
    params = urllib.urlencode({'level': 'FINE', 'startTime': startTime, 'endTime': endTime, 'filter':logFilter, 'token': token, 'f': 'json'})
    
    headers = {"Content-type": "application/x-www-form-urlencoded", "Accept": "text/plain"}
    
    # Connect to URL and post parameters    
    httpConn = httplib.HTTPConnection(serverName, serverPort)
    httpConn.request("POST", logQueryURL, params, headers)
    
    # Read response
    response = httpConn.getresponse()
    if (response.status != 200):
        httpConn.close()
        print "Error while querying logs."
        return
    else:
        data = response.read()

        # Check that data returned is not an error object
        if not assertJsonSuccess(data):          
            print "Error returned by operation. " + data
        else:
            print "Operation completed successfully!"

        # Deserialize response into Python object
        dataObj = json.loads(data)
        httpConn.close()

        # Need these variables to calculate average draw time for an ExportMapImage call
        mapDraws = 0
        totalDrawTime = 0 
        
        # Iterate over messages        
        for item in dataObj["logMessages"]:
            
                       
            if item["message"] == "End ExportMapImage":

                elapsed = float(item["elapsed"])
                keyCheck = item["source"]

                if keyCheck in hitDict:
                    stats = hitDict[keyCheck]

                    # Add 1 to tally of hits
                    stats[0] += 1
                    
                    # Add elapsed time to total elapsed time
                    stats[1] += elapsed
                else:
                    # Add key with one hit and total elapsed time
                    hitDict[keyCheck] = [1,elapsed]

        # Open text file and write header line       
        summaryFile = open(filePath, "w")        
        header = "Service,Number of hits,Average seconds per draw\n"
        summaryFile.write(header)

        # Read through dictionary and write totals into file 
        for key in hitDict:

            # Calculate average elapsed time
            totalDraws = hitDict[key][0]
            totalElapsed = hitDict[key][1]
            avgElapsed = 0

            if totalDraws > 0:     
                avgElapsed = (1.0 * (totalElapsed / totalDraws)) #Elapsed time divided by hits

            # Construct and write the comma-separated line         
            line = key + "," + str(totalDraws) + "," + str(avgElapsed) + "\n"
            summaryFile.write(line)

        summaryFile.close()
        return

#A function to generate a token given username, password and the adminURL.
def getToken(username, password, serverName, serverPort):
    # Token URL is typically http://server[:port]/arcgis/admin/generateToken
    tokenURL = "/arcgis/admin/generateToken"
    
    # URL-encode the token parameters
    params = urllib.urlencode({'username': username, 'password': password, 'client': 'requestip', 'f': 'json'})
    
    headers = {"Content-type": "application/x-www-form-urlencoded", "Accept": "text/plain"}
    
    # Connect to URL and post parameters
    httpConn = httplib.HTTPConnection(serverName, serverPort)
    httpConn.request("POST", tokenURL, params, headers)
    
    # Read response
    response = httpConn.getresponse()
    if (response.status != 200):
        httpConn.close()
        print "Error while fetching tokens from admin URL. Please check the URL and try again."
        return
    else:
        data = response.read()
        httpConn.close()
        
        # Check that data returned is not an error object
        if not assertJsonSuccess(data):            
            return
        
        # Extract the toke from it
        token = json.loads(data)       
        return token['token']            
        

#A function that checks that the input JSON object
#  is not an error object.    
def assertJsonSuccess(data):
    obj = json.loads(data)
    if 'status' in obj and obj['status'] == "error":
        print "Error: JSON object returns an error. " + str(obj)
        return False
    else:
        return True
    
        
# Script start
if __name__ == "__main__":
    sys.exit(main(sys.argv[1:]))