algorithm - How is Amazon SQS visibility timeout implemented? -


i wondering how efficient implementation of sqs visibility timeout looks like. messages put in queue , worker sweeps on , removes reached timeout threshold?

i implement storing timestamp says when make visible.

  • during receivemessage(), not return messages timestamp < now
  • in management console, show timestamp < now messages in flight
  • when timestamp >= now, nothing!

while there lot of timestamp comparisons, no worse checking status code. plus, there's no need clear timestamp when time has past, "efficient" in no 'sweep' processes required.

amazon sqs highly distributed across multiple servers , multiple availability zones, efficient avoid possible data update since need replicated amongst servers.


-

Comments

Post a Comment

Popular posts from this blog

java - SSE Emitter : Manage timeouts and complete() -

i writing web app multiple listeners(evcentsource sse clients js) connected server . want store sse emitter per connected listener : can done in memory or other means assigning id each client able achieve far now question ; how send response/event specific client connected web app ? while doing sseemmiters stored either getting completed or timed out. how prevent ? how keep sseemmiter available open infinite time (till client closes) , send events selectively .
Read more

jquery - uncaught exception: DataTables Editor - remote hosting of code not allowed -

i'm trying implement crud operation using datatableseditor using datatables.but i'm getting error messages: 1)uncaught exception: datatables editor - remote hosting of code not allowed. please see http://editor.datatables.net details on how purchase editor license 2)typeerror: a.editor undefined 3) $.fn.datatable.editor not constructor" what reason? here configuration: <%@ page language="java" contenttype="text/html; charset=iso-8859-1" pageencoding="iso-8859-1"%> <!doctype html public "-//w3c//dtd html 4.01 transitional//en" "http://www.w3.org/tr/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=iso-8859-1"> <title>insert title here</title> <link rel="stylesheet" type="text/css" href="//cdn.datatables.net/1.10.12/css/jquery.datatables.min.css"> <link re...
Read more

java - How to resolve error - package com.squareup.okhttp3 doesn't exist? -

i trying convert json java object use of gson in maven, following youtube video guidance - https://www.youtube.com/watch?v=vqgghm9pwe0 , theres error occurs when in main class error - package com.squareup.okhttp3 doesn't exist. code below: java package com.codebeasty.json; import com.squareup.okhttp3.okhttpclient; public class main { private static okhttpclient client = new okhttpclient(); public static void main (string [] args) { } } i put in dependency in pom.xml: <dependencies> <dependency> <groupid>com.squareup.okhttp3</groupid> <artifactid>okhttp</artifactid> <version>3.4.2</version> </dependency> <dependency> <groupid>com.google.code.gson</groupid> <artifactid>gson</artifactid> <version>2.8.0</version> </dependency> </dependencies> i dont understand why doesn't recognize com.squareup. there may need download? have downl...
Read more