public async Task <SummarizedDnsServerStatistics> SummarizeTimeSpanForSingleServer(TimeSpan timeSpanToSummarize, string serverName)
{
if (timeSpanToSummarize <= TimeSpan.Zero)
{
throw new ArgumentOutOfRangeException($"TimeSpan must be positive ant non-zero, got: {timeSpanToSummarize}");
}
if (serverName == "all" || serverName == "blitz")
{
return((await SummarizeTimeSpan(timeSpanToSummarize)).First(result => result.ServerName == serverName));
}
var fromDate = DateTime.UtcNow.Subtract(timeSpanToSummarize);
var serverStatistics = await _dnsServerStatisticsStore.GetServerStatisticsFromDate(serverName, fromDate);
return(new SummarizedDnsServerStatistics(serverStatistics));
}
/// <summary>
/// Get DNS server statistics for all servers
/// </summary>
/// <returns></returns>
private async Task <List <DnsServerStatistics> > GetAllDnsServerStatistics()
{
var allDnsServerStatistics = new List <DnsServerStatistics>();
foreach (var server in _dnsServersSettings.DnsServers)
{
allDnsServerStatistics.AddRange(await _dnsServerStatisticsStore.GetServerStatisticsFromDate(server.ServerName, DateTime.UtcNow.AddHours(-HoursToSummarize)));
}
return(allDnsServerStatistics);
}
/// <summary>
/// Get DNS server statistics for a single server.
/// First, try get statistics from memory cache, and if not exist, query storage
/// </summary>
/// <param name="server"></param>
/// <returns></returns>
private async Task <List <DnsServerStatistics> > GetDnsServerStatistics(string server)
{
if (!_memoryCache.TryGetValue(server, out IEnumerable <DnsServerStatistics> dnsServerStatistics))
{
dnsServerStatistics = await _dnsServerStatisticsStore.GetServerStatisticsFromDate(server, DateTime.UtcNow.AddDays(-1));
var cacheEntryOptions = new MemoryCacheEntryOptions().SetAbsoluteExpiration(TimeSpan.FromMinutes(20)).SetSlidingExpiration(TimeSpan.FromMinutes(10));
_memoryCache.Set(server, dnsServerStatistics, cacheEntryOptions);
}
return(dnsServerStatistics?.ToList());
}
public static async Task Run(
[TimerTrigger("0 0 19 * * *")] TimerInfo myTimer,
[Inject] IOptions <DnsServersSettings> dnsServersSettings,
[Inject] IDnsServerStatisticsStore dnsServerStatisticsStore,
[Inject] IEnumerable <IAlertClient> alertClients)
{
var logger = Log.ForContext("SourceContext", FunctionName);
try
{
var hoursOfIncrements = DateTime.UtcNow.GetHoursOfIncrements();
var printableTimeSpan = hoursOfIncrements.PrintableTimeSpan();
// Get statistics for all servers
var allDnsServerStatistics = new List <DnsServerStatistics>();
foreach (var server in dnsServersSettings.Value.DnsServers)
{
allDnsServerStatistics.AddRange(await dnsServerStatisticsStore.GetServerStatisticsFromDate(server.ServerName, DateTime.UtcNow.AddHours(-hoursOfIncrements)));
}
if (allDnsServerStatistics.Count == 0)
{
throw new InvalidOperationException($"Did not get any statistical increments for pidns servers for hours {hoursOfIncrements}");
}
var totalNumQueries = allDnsServerStatistics.Sum(s => s.TotalNumQueries);
var totalAdsBlocked = allDnsServerStatistics.Sum(s => s.NumAnswerNXDOMAIN);
foreach (var alertClient in alertClients)
{
logger.Information("Sending pidns statistics totalNumQueries {TotalNumQueries} and totalAdsBlocked {TotalAdsBlocked} to {Integration} client",
totalNumQueries, totalAdsBlocked, alertClient.Integration);
if (!(await alertClient.TrySendPiDnsStatistics(totalNumQueries, totalAdsBlocked, printableTimeSpan)))
{
logger.Warning("AlertClient {Client} returned false when sending pidns statistics alert, indicating a failure", alertClient.Integration);
}
}
}
catch (Exception e)
{
logger.Error(e, "Got an exception while processing pidns statistics alert");
}
}
private async Task <IOrderedEnumerable <DnsServerStatistics> > GetStatisticsForSingleServer(string serverName, DateTime fromDate)
{
return(await _dnsServerStatisticsStore.GetServerStatisticsFromDate(serverName, fromDate));
}
