Files
raven/server/AyaNova/util/ReportProcessManager.cs

121 lines
5.4 KiB
C#

using System;
using System.Collections.Concurrent;
using System.Diagnostics;
using Microsoft.Extensions.Logging;
namespace AyaNova.Util
{
/// <summary>
/// Used by reporting system to ensure headless browsers don't hang around in an untimely manner chewing up resources
/// needed due to bugs in puppeteersharp where it won't close the browser on timeout properly
/// also zombie process issues in linux etc, this just ensures it's safe
/// This is triggered when a report is rendered on demand
/// in other words demand drives whether it kills long running renders or not
/// this is by design to allow a scenario where a super long running report can still be run off hours (for example)
/// </summary>
internal static class ReportRenderManager
{
/*
expired processes are removed by the act of tryign to get a new slot so in this way it still supports running super long reports overnight for example as long as there is no contention
The other way was by a job that looks for expired processes but that would mean all old jobs would expire all the time so there would be an issue with huge reports never working
*/
//thread safe collection for unordered items, optimized for single thread produce/consume (which is the norm here) but supports multithread produce / consume (which is needed for separate cleanup job)
private static ConcurrentBag<ReportRenderInstanceInfo> _baginstances = new ConcurrentBag<ReportRenderInstanceInfo>();
public class ReportRenderInstanceInfo
{
public int ReporterProcessId { get; set; }
public DateTime Expires { get; set; }
public ReportRenderInstanceInfo(int processId)
{
ReporterProcessId = processId;
Expires = DateTime.UtcNow.AddMilliseconds(ServerBootConfig.AYANOVA_REPORT_RENDERING_TIMEOUT);
}
}
public static bool RenderSlotAvailable(ILogger log)
{
log.LogTrace("RenderSlotAvailable check");
var count = _baginstances.Count;
// #if (DEBUG)
// log.LogInformation($"DBG: RenderSlotAvailable check, there are currently {count} instances in the bag");
// #endif
if (count >= ServerBootConfig.AYANOVA_REPORT_RENDERING_MAX_INSTANCES)
{
log.LogTrace($"RenderSlotAvailable there are no free report rendering slots available, current count is {count}, checking for expired slots to force closed");
//check for expired and remove
var Instances = _baginstances.ToArray();
var dtNow = DateTime.UtcNow;
foreach (ReportRenderInstanceInfo i in Instances)
{
if (i.Expires < dtNow)
{
// #if (DEBUG)
// log.LogInformation($"DBG: RenderSlotAvailable attempting kill of expired process {i.ReporterProcessId}");
// #endif
ForceCloseProcess(i, log);
}
}
}
//allow to continue if there are now fewer than max instances in the bag
return _baginstances.Count < ServerBootConfig.AYANOVA_REPORT_RENDERING_MAX_INSTANCES;
}
private static bool ForceCloseProcess(ReportRenderInstanceInfo instance, ILogger log)
{
log.LogTrace($"ForceCloseProcess on instance id {instance.ReporterProcessId} started {instance.Expires.ToString()} utc");
try
{
var p = Process.GetProcessById(instance.ReporterProcessId);
if (p != null)
{
//we have an existing process
//try to kill it
p.Kill();
if (p.HasExited == false)
{
log.LogDebug($"RenderSlotAvailable oldest slot could not be stopped");
return false;//can't kill it so can't free up a slot
}
}
//remove it from the list, it's either gone or killed at this point
//this would not be unexpected since it will normally just close on it's own
//at the finally in render report
_baginstances.TryTake(out instance);
return true;//process that was there is now not there so while not perfect system we will consider it free
}
catch (ArgumentException)
{
//do nothing, this is normal, the process could not be found and this means it's already been removed:
//ArgumentException
//The process specified by the processId parameter is not running. The identifier might be expired.
_baginstances.TryTake(out instance);
return true;
}
}
internal static void AddProcess(int processId)
{
_baginstances.Add(new ReportRenderInstanceInfo(processId));
}
internal static void RemoveProcess(int processId, ILogger log)
{
foreach (var i in _baginstances)
{
if (i.ReporterProcessId == processId)
{
ForceCloseProcess(i, log);
break;
}
}
}
}//eoc
}//eons