1 /* 2 * Copyright (C) 2019 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.net.util; 18 19 /** 20 * Collection of utilities for data stall. 21 */ 22 public class DataStallUtils { 23 /** 24 * Detect data stall via using dns timeout counts. 25 */ 26 public static final int DATA_STALL_EVALUATION_TYPE_DNS = 1; 27 // Default configuration values for data stall detection. 28 public static final int DEFAULT_CONSECUTIVE_DNS_TIMEOUT_THRESHOLD = 5; 29 public static final int DEFAULT_DATA_STALL_MIN_EVALUATE_TIME_MS = 60 * 1000; 30 public static final int DEFAULT_DATA_STALL_VALID_DNS_TIME_THRESHOLD_MS = 30 * 60 * 1000; 31 /** 32 * The threshold value for the number of consecutive dns timeout events received to be a 33 * signal of data stall. The number of consecutive timeouts needs to be {@code >=} this 34 * threshold to be considered a data stall. Set the value to {@code <= 0} to disable. Note 35 * that the value should be {@code > 0} if the DNS data stall detection is enabled. 36 * 37 */ 38 public static final String CONFIG_DATA_STALL_CONSECUTIVE_DNS_TIMEOUT_THRESHOLD = 39 "data_stall_consecutive_dns_timeout_threshold"; 40 41 /** 42 * The minimal time interval in milliseconds for data stall reevaluation. 43 * 44 */ 45 public static final String CONFIG_DATA_STALL_MIN_EVALUATE_INTERVAL = 46 "data_stall_min_evaluate_interval"; 47 48 /** 49 * DNS timeouts older than this timeout (in milliseconds) are not considered for detecting 50 * a data stall. 51 * 52 */ 53 public static final String CONFIG_DATA_STALL_VALID_DNS_TIME_THRESHOLD = 54 "data_stall_valid_dns_time_threshold"; 55 56 /** 57 * Which data stall detection signal to use. This is a bitmask constructed by bitwise-or-ing 58 * (i.e. {@code |}) the DATA_STALL_EVALUATION_TYPE_* values. 59 * 60 * Type: int 61 * Valid values: 62 * {@link #DATA_STALL_EVALUATION_TYPE_DNS} : Use dns as a signal. 63 */ 64 public static final String CONFIG_DATA_STALL_EVALUATION_TYPE = "data_stall_evaluation_type"; 65 public static final int DEFAULT_DATA_STALL_EVALUATION_TYPES = DATA_STALL_EVALUATION_TYPE_DNS; 66 // The default number of DNS events kept of the log kept for dns signal evaluation. Each event 67 // is represented by a {@link com.android.server.connectivity.NetworkMonitor#DnsResult} objects. 68 // It's also the size of array of {@link com.android.server.connectivity.nano.DnsEvent} kept in 69 // metrics. Note that increasing the size may cause statsd log buffer bust. Need to check the 70 // design in statsd when you try to increase the size. 71 public static final int DEFAULT_DNS_LOG_SIZE = 20; 72 } 73