Exemple : dérivation de statistiques de service de carte à partir des journaux ArcGIS for Server

L'exemple d'API REST d'ArcGIS vous explique comment explorer les journaux d'ArcGIS Server à la recherche de statistiques sur les divers services. Le script ci-dessous lit les messages relatifs aux affichages de carte terminés, consignés au cours des dernières 24 heures. Il assure le suivi des services qui ont été dessinés, ainsi que de la durée nécessaire pour l'affichage. Il écrit ensuite un fichier texte délimité par des virgules qui résume le nombre d'affichages et la durée d'affichage moyenne pour chaque service.

Pour essayer cet exemple, procédez comme suit :

1. Publiez plusieurs services de carte (sans leur appliquer de caches de tuile).
2. Définissez le niveau de consignation d'ArcGIS Server sur Détaillé.
3. Soumettez des requêtes d'affichage de vos services en les ajoutant à ArcMap ou en cliquant sur leurs miniatures dans le Gestionnaire, puis en effectuant un zoom et un déplacement.
4. Exécutez ce script et examinez le fichier texte obtenu. Vous pouvez même renommer le fichier avec une extension .csv et l'ouvrir dans un tableur, tel que Microsoft Excel.

# 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:]))