Vea haldus ja logiraamat hajutatud süsteemides Enn Õunapuu enn.ounapuu@ttu.ee
Millest tuleb jutt? Kuidas ma näen, millises sammus erinevad protsessid parasjagu on? Kuidas ma aru saan, kas protsess töötab või on katkenud? Kuidas ma vea tekkimisel näen, millises süsteemis viga tekkis? Kuidas luua protsess selliselt, et vea kõrvaldamisel saaks protsess jätkuda? Kuidas ma tagan erinevate süsteemide vahel andmete terviklikkuse?
Hajusa süsteemi omapära veatootluse ja jälgitavuse seisukohalt
Tegevuste analüüs
Preliminaries: Data Logging Keeping track of execution data Activities that have been carried out Timestamps (Start and end times of activities) Resources involved Data Purposes Audit trails Disaster recovery Monitoring Data Mining Process Mining Process Simulation
Preliminaries: Process Mining Event logs (recorded actual behaviors) Covers a wide-range of techniques Provide insights into control flow dependencies data usage resource involvement performance related statistics etc. Identify problems that cannot be identified by inspecting a static model alone
Preliminaries: Process Simulation Develop a simulation model at design time Carry out experiments under different assumptions Used for process reengineering decisions Data input is time-consuming and error-prone Requires careful interpretation Abstraction of the actual behavior Different assumptions made Inaccurate or Incomplete data input Starts from an empty initial state
Process Mining Process discovery: "What is really happening?" Conformance checking: "Do we do what was agreed upon?" Performance analysis: "Where are the bottlenecks?" Process prediction: "Will this case be late?" Process improvement: "How to redesign this process?" Etc.
Process mining: Linking events to models world business processes people machines components organizations models analyzes supports/ controls specifies configures implements analyzes software system records events, e.g., messages, transactions, etc. process/ system model discovery conformance event logs
Where to start? process control diagnosis process mining process enactment process design implementation/ configuration
Veatöötlus harilikus rakenduses protected void Button5_Click(object sender, EventArgs e) { try { Label1.Text = Convert.ToString(Convert.ToInt32(TextBox1.Text) / Convert.ToInt32(TextBox2.Text)); } catch (Exception ee) { logger.error("ennu error message.jagamine nulliga"); Label1.Text = ee.message; } }
Jälgitavus Kuidas teada saada, mis hajutatud süsteemis toimub? Milline protsesside efektiivusus? Millised on vead ja eriolukorrad? Kuidas neid käsitleda?
Arutelu hajusa süsteemi näitel? Vaatleme krediitkaardiga maksmist. Kõik tundub lihtne. Kontrollitakse, kas on piisavalt vahendeid ja teostatakse makse. Süvenemisel, tekib terve rida eriolukordi, mis nõuavad lahendust. Mis teha siis, kui vastus ei saabunud õigeaegselt? Kuidas kontrollida, et maksja on krediitkaardi omanik?
nlog süsteem NLog can process diagnostic messages emitted from any.net language (such as C# or Visual Basic), augment them with contextual information (such as date/time, severity, thread, process, environment enviroment), format them according to your preference and send them to one or more targets such as file or database.
Nlog järg NLog is very easy to use and configure, both through Configuration File and programmatically at runtime. Advanced routing options include buffering, asynchronous logging, load balancing, failover, and more. Log output options include: Files - single file or multiple, with automatic file naming and archival Event Log - local or remote Database - store your logs in databases supported by.net Network - using TCP, UDP, SOAP, MSMQ protocols Command-line console - including color coding of messages E-mail - you can receive emails whenever application errors occur ASP.NET trace
Demo Remote desktop nloglogging
Google analytics Web analytics definition: The analysis of qualitative and quantitative data from your website and the competition, to drive a continual improvement of the online experience that your customers, and potential customers have, which translates into your desired outcomes (online and offline).
Demo http://www.google.com/analytics/
nlog config <?xml version="1.0" encoding="utf-8"?> <nlog xmlns="http://www.nlog-project.org/schemas/nlog.xsd" xmlns:xsi="http://www.w3.org/2001/xmlschema-instance"> <targets> <target name="queue" xsi:type="msmq" layout="${message}" queue=".\private$\nlog" encoding="iso-8859-2" recoverable="true" label="${logger}"/> </targets> <rules> <logger name="*" minlevel="debug" writeto="queue"/> </rules> </nlog>
Kasutamine programmis using Nlog; namespace NlogLogging { public partial class _Default : System.Web.UI.Page { private static Logger logger = LogManager.GetLogger("IDU0080"); protected void Page_Load(object sender, EventArgs e) { Application.Lock(); Application["PageRequestCount"] = ((int)application["pagerequestcount"]) + 1; Application.UnLock(); logger.trace("ennu trace teade,session:" + Application["PageRequestCount"].ToString()); logger.debug("ennu debug message,session:" + Application["PageRequestCount"].ToString()); logger.info("ennu informational message,session:" + Application["PageRequestCount"].ToString()); logger.warn("ennu warning message,session:" + Application["PageRequestCount"].ToString()); logger.error("ennu error message,session:" + Application["PageRequestCount"].ToString()); logger.fatal("ennu fatal error message,session:" + Application["PageRequestCount"].ToString()); // alternatively you can call the Log() method // and pass log level as the parameter. // logger.log(loglevel.info, "Sample fatal error message");
Protsessi algus ja lõpp protected void Button1_Click(object sender, EventArgs e) { logger.info("ennu Esimene process startis,session:" + Application["PageRequestCount"].ToString()); System.Threading.Thread.Sleep(3500); logger.info("ennu Esimene process lopetas,session:" + Application["PageRequestCount"].ToString()); }
Eriolukord protected void Button5_Click(object sender, EventArgs e) { try { Label1.Text = Convert.ToString(Convert.ToInt32(TextBox1.Text) / Convert.ToInt32(TextBox2.Text)); } catch (Exception ee) { logger.error("ennu error message.jagamine nulliga,session:" + Application["PageRequestCount"].ToString()); Label1.Text = ee.message; } }
Jõudu!!!