public static string GetMessage(LttngReaderStatusCode error)
{
switch (error)
{
case LttngReaderStatusCode.END_OF_TRACE: return("Success - End of trace reached.");
case LttngReaderStatusCode.SUCCESS: return("Success - No error found during execution.");
case LttngReaderStatusCode.FAILED_TO_READ_EVENT: return("Recoverable Error - Failed to read single event. It may be possible to continue reading traces.");
case LttngReaderStatusCode.ERROR: return("Unrecoverable error happened when trying to read event. Unable to proceed processing traces.");
case LttngReaderStatusCode.NOT_ENOUGH_MEM: return("Failed allocating memory.");
case LttngReaderStatusCode.INVALID_BUFFER_SIZE: return("Not enough space in buffer provided.");
case LttngReaderStatusCode.INVALID_ARGUMENT: return("One of the provided arguments is not valid.");
case LttngReaderStatusCode.NO_LTTNG_SESSION_FOUND: return("No active LTTng trace session found.");
case LttngReaderStatusCode.FAILED_TO_LOAD_TRACES: return("Failed opening trace folder for reading traces.");
case LttngReaderStatusCode.FAILED_INITIALIZING_TRACEINFO: return("Failure when initializing trace.");
case LttngReaderStatusCode.FAILED_TO_MOVE_ITERATOR: return("Failure occuring when trying to move iterator to next event.");
case LttngReaderStatusCode.INVALID_CTF_ITERATOR: return("Invalid (null) CTF iterator provided.");
case LttngReaderStatusCode.UNEXPECTED_END_OF_TRACE: return("Unexpectedly reached the end of the trace.");
default:
return("Invalid error code provided.");
}
}
private void InitializeTraceHandle()
{
if (this.traceHandle.id < 0)
{
// initializing for reading traces with iterator at oldest trace event so we can query the total number of events lost in the session.
StringBuilder sbPath = new StringBuilder();
sbPath.Append(this.path);
// trace is always initialized with first and last events since
// the timerange is always reset for each ReadEvents call
LttngReaderStatusCode res = LttngReaderBindings.initialize_trace_processing(
sbPath,
(ulong)LTTngTraceTimestampFlag.FIRST_TRACE_TIMESTAMP,
(ulong)LTTngTraceTimestampFlag.LAST_TRACE_TIMESTAMP,
out this.traceHandle);
if (res != LttngReaderStatusCode.SUCCESS)
{
string errorMessage = LttngReaderStatusMessage.GetMessage(res);
throw new InvalidDataException($"{errorMessage}. Occured while trying to initialize processing of LTTng traces for folder {this.path}");
}
this.EventsLost = (uint)this.traceHandle.trace_info.events_lost;
}
}
public void ReadEvents(DateTime startTime, DateTime endTime)
{
if (startTime > endTime)
{
throw new ArgumentException(StringResources.ETLReaderError_StartTimeGreaterThanEndTime, "startTime");
}
if (this.EventRead == null)
{
throw new InvalidOperationException(StringResources.ETLReaderError_NoSubscribersForEventRead);
}
// initialize trace handle
InitializeTraceHandle();
ulong eventReadFailureCount;
LttngReaderStatusCode res = ProcessTrace(startTime, endTime, ref this.traceHandle, out eventReadFailureCount);
if (res != LttngReaderStatusCode.SUCCESS && res != LttngReaderStatusCode.END_OF_TRACE)
{
string errorMessage = LttngReaderStatusMessage.GetMessage(res);
throw new InvalidDataException(
$"{errorMessage}. When processing traces at folder: {this.path}.\n" +
$"Last event successfully read has timestamp: {LttngTraceFolderEventReader.ConvertFromUnixEpoch(this.lastEventReadTimestamp).ToString("o")}\n" +
$"Total events events skipped due to failure before exception : {eventReadFailureCount}");
}
if (eventReadFailureCount != 0)
{
throw new InvalidDataException(
$"Failed to read {eventReadFailureCount} events from trace at {this.path}" +
$"StartTime: {startTime}, EndTime: {endTime}");
}
}
private string GetServiceFabricSessionOutputPath()
{
StringBuilder serviceFabricSessionName = new StringBuilder(LttProducerWorker.ServiceFabricSessionName);
StringBuilder serviceFabricSessionOutputPath = new StringBuilder(LttProducerWorker.PathMaxSize);
// If processing traces from container LTTng session the session is not accessible from host.
// In this case the the active session is the one and only one folder inside the Log/Containers/sf-containerid/lttng-traces folder.
string containerTraceFolder;
if (this.TryGetContainerTraceFolder(out containerTraceFolder))
{
return(containerTraceFolder);
}
LttngReaderStatusCode res = LttngReaderBindings.get_active_lttng_session_path(serviceFabricSessionName, serviceFabricSessionOutputPath, LttProducerWorker.PathMaxSize);
if (res == LttngReaderStatusCode.SUCCESS)
{
return(serviceFabricSessionOutputPath.ToString().TrimEnd(Path.DirectorySeparatorChar));
}
else
{
string errorMessage = LttngReaderStatusMessage.GetMessage(res);
this.traceSource.WriteWarning(
this.logSourceId,
"Unable to find active Service Fabric Ltt trace session with name starting with: {0}.\nInner error : {1}",
LttProducerWorker.ServiceFabricSessionName,
errorMessage);
}
return(null);
}
private LttngReaderStatusCode ProcessTrace(DateTime startTime, DateTime endTime, ref LTTngTraceHandle traceHandle, out ulong eventReadFailureCount)
{
EventRecord eventRecord = new EventRecord();
ulong lastReadTimestamp = 0;
// needed for processing unstructured events in Linux
bool isUnstructured = false;
StringBuilder unstructuredRecord = new StringBuilder(LttngReaderBindings.MAX_LTTNG_UNSTRUCTURED_EVENT_LEN + 1);
StringBuilder taskNameEventName = new StringBuilder(LttngReaderBindings.MAX_LTTNG_TASK_EVENT_NAME_LEN + 1);
ulong startTimeEpochNanoS = LttngTraceFolderEventReader.ConvertToUnixEpoch(startTime);
ulong endTimeEpochNanoS = LttngTraceFolderEventReader.ConvertToUnixEpoch(endTime);
// set start and end time for reading traces
LttngReaderStatusCode res = LttngReaderBindings.set_start_end_time(ref traceHandle, startTimeEpochNanoS, endTimeEpochNanoS);
eventReadFailureCount = 0;
if (res != LttngReaderStatusCode.SUCCESS)
{
return(res);
}
res = LttngReaderBindings.read_next_event(ref traceHandle, ref eventRecord, unstructuredRecord, taskNameEventName, ref lastReadTimestamp, ref isUnstructured);
while (res == LttngReaderStatusCode.SUCCESS || res == LttngReaderStatusCode.FAILED_TO_READ_EVENT)
{
if (res == LttngReaderStatusCode.FAILED_TO_READ_EVENT)
{
eventReadFailureCount++;
continue;
}
EventRecordEventArgs eventRecordEventArgs;
this.lastEventReadTimestamp = lastReadTimestamp;
if (isUnstructured)
{
try
{
eventRecord.EventHeader.TimeStamp = LttngTraceFolderEventReader.ConvertFromUnixEpoch(lastReadTimestamp).ToFileTimeUtc();
}
catch (Exception)
{
// Flagging error with minimum timestamp so we can continue processing other events.
eventRecord.EventHeader.TimeStamp = 0;
}
eventRecordEventArgs = new EventRecordEventArgs(eventRecord);
eventRecordEventArgs.IsUnstructured = isUnstructured;
eventRecordEventArgs.TaskNameEventName = taskNameEventName.ToString();
eventRecordEventArgs.UnstructuredRecord = unstructuredRecord.ToString();
}
else
{
eventRecordEventArgs = new EventRecordEventArgs(eventRecord);
}
this.EventRead(this, eventRecordEventArgs);
if (eventRecordEventArgs.Cancel)
{
return(LttngReaderStatusCode.SUCCESS);
}
res = LttngReaderBindings.read_next_event(ref traceHandle, ref eventRecord, unstructuredRecord, taskNameEventName, ref lastReadTimestamp, ref isUnstructured);
}
return(res);
}
