Is there an TSI-Endpoint that provides the most recent message of a time series that arrived from e.g. an iot-hub? In my current situation I have to poll a certain period of time (for example now to 30 seconds in the past) and I wonder if there is a better way to do this?
Unfortunately there is no endpoint that lets you query only the last event. You can use GetEvents and query over the last 30 seconds, like you said, or peek the last message from the Event Hub/IoT Hub.
Related
This is the data recording reported by sensor and its being updated in every 20mins
Sensor Reading
In this case, I would like to find out the outage time period. Anyone can suggest on how to find the outage time. Like in the picture shown above that the down time occurs at 40 minutes long.
I am building an event reminder page where people can set a reminder for certain events. There is an option for the user to set the amount of time before they need to be notified. It is stored in notification_time and notification_unit. notification_time keeps track of the time before they want to be notified and notification_unit keeps track of the PHP date format in which they selected the time, eg. i for minutes, H for hours.
Eg. notification_time - 2 and notification_unit - H means they need to be notified 2 hours before.
I have Cron jobs running in the background for handling the notification. This function is being hit once every minute.
Reminder::where(function ($query) {
$query->where('event_time', '>=', now()->subMinutes(Carbon::createFromFormat('i', 60)->diffInMinutes() - 1)->format('H:i:s'));
$query->where('event_time', '<=', now()->subMinutes(Carbon::createFromFormat('i', 60)->diffInMinutes())->format('H:i:s'));
})
In this function, I am hard coding the 'i', 60 while it should be fetched from the database. event_time is also part of the same table
The table looks something like this -
id event_time ... notification_unit notification_time created_at updated_at
Is there any way to solve this issue? Is it possible to do the same logic with SQL instead?
A direct answer to this question is not possible. I found 2 ways to resolve my issue.
First solution
Mysql has DATEDIFF and DATE_SUB to get timestamp difference and subtract certain intervals from a timestamp. In my case, the function runs every minute. To use them, I have to refactor my database to store the time and unit in seconds in the database. Then do the calculation. I chose not to use this way because both operations are a bit heavy on the server-side since I am running the function every minute.
Second Solution
This is the solution that I personally did in my case. Here I did the calculations while storing it in the database. Meaning? Let me explain. I created a new table notification_settings which is linked to the reminder (one-one relation). The table looks like this
id, unit, time, notify_at, repeating, created_at, updated_at
The unit and time columns are only used while displaying the reminder. What I did is, I calculated when to be notified in the notify_at column. So in the event scheduler, I need to check for the reminders at present (since I am running it every minute). The repeating column is there to keep track of whether the reminder is repeating or not. If it is repeating I re-calculate the notify_at column at the time of scheduling. Once the user is notified notify_at is set to null.
I've been looking at a recent event in Splunk with sourcetype WinHostMon, and I see two different values for StartTime and _time:
StartTime="20200427223006.448182-300"
_time is recorded as 2020-04-28T15:38:13.000-04:00
If the last part is timezone, there are two things that are strange about this:
The timezone for StartTime is in the middle of the Atlantic.
The times don't actually match.
Question: What is the actual time of this event, if such a thing can actually be determined, and what is causing the discrepancy between these two times?
(I tried to post this on Splunk Answers but they seem to have a labyrinth to stop people from signing up and I was unable to get an activated account.)
_time is the timestamp of the event, that is, when the event was generated or written to a log file. This is the field Splunk uses for default sorting and rendering in tables and time charts.
For WinHostMon events, most notably Process events, StartTime is when that process started.
Hence, it is not surprising that these events are significantly different. The process may have started at some point in the past, and then the WinHostMon input may generate a list of active processes every 5 minutes or so (or more or less)
_time is the timestamp of the event as defined in props.conf - or, if undefined, whenever Splunk receives the event (as often happens with untagged JSON)
The field StartTime is - so far as I can tell - not related to whatever is populating _time
If you open the Add-On's props.conf, you'll see how they're defining the timestamp and the field extraction for StartTime
I have a batch job that runs once per day.
At the end of the job I submit a meter metric with a count of the items processed.
I want to alert if one day this metric is not updated.
On http://metrics.librato.com the maximum time I can check "not reported for" when creating an alert is 60 minutes.
I thought maybe I can create a composite metric and take the avg rate of change over the past 24 hours, and alert if that reaches zero.
I've been trying:
derive(s("my.metric", "%", {function:"sum", period:"86400"}))
However it seems that, because I log only a single event, above quite small values of period (~250s) my rate of change simply drops to zero ...I guess the low frequency means my single value is completely lost by the sampling.
Maybe I am using the wrong tool for the job...
Is there a way to achieve this in Librato?
There currently is not a way to achieve this as composite metrics are subject to the 60 minute limitation of alerts as well (as of 5/15/2015). You may need to look into configuring the metric (or a similar metric) to report within the 60m time range if possible.
OK, let's say I am writing a calendar application in which a user can create an event. An event can occur in the following situations:
1 time only.
Every Period of time keep reply, until a day.
Every Period of time keep reply, until a day, except some days.
Every some kind of week day.
Let me explain in a detailed example:
1 time only: 24/8/2011 ONLY.
Every Period of time keep reply, until a day: 25/8/2011 Start, and every week end will have this event, until 30/10/2011.
Every Period of time keep reply, until a day, except some days: 25/8/2011 Start, and every week end will have this event, until 30/10/2011, except the 10/09/2011 and 17/09/2011.
Every some kind of week day, .
Every some kind of week day, except some days.
Martin Fowler wrote a nice big article about just this topic a few years ago. Rather than repeat his analysis, I'll just point you at the pdf. It's called Recurring Events For Calendars.