Zabbix trigger of drop user - triggers

My question : is it possible to have a trigger on that item that will be activated if there's a difference of xx% between the two last queries ?
Example :
Query at 01:00 -> 2000 users connected
Query at 01:10 -> 2100 users, difference is positive, we don't care
Query at 01:20 -> 2050 users, -50 users, around 2-3%, no big deal
Query at 01:30 -> 800 users, around 60% less connections, there's something wrong here
Is it possible to have a trigger that activates when the difference is, let's say, 20% negative ?

You can use the abschange function:
The amount of absolute difference between last and previous values
to alert for both positive and negative changes.
Or you can use the last function to get the latest values you need:
For example:
last() is always equal to last(#1)
last(#3) - third most recent value (not three latest values)
In both cases you need to compute the % value in your trigger with the usual proportion:
older_value:100 = newer_value:x

Related

Find count of active users in the last 29 days in Tableau

Require assistance in calculating the Total Active Users from March 16 2020 to Feb 16 2020.
I have tried using calculated fields, but not getting the correct results. Please advise.
Thank you,
Nirmal
To find the number of unique values that appear in a field, say [user_code], you can use the COUNT DISTINCT function, COUNTD() as in COUNTD([user_code])
To restrict the data to a particular time range, one way is put your date field on the Filter shelf and choose the settings that include only the data rows you want — say the range from 2/16 to 3/16 as you stated.
Alternatively, you can push the filtering condition into the calculation with an IF function call, as in COUNTD(IF <data is relevant> THEN [user_code] END) Thus effectively combining the two techniques. That works because if there is no ELSE clause and the IF condition is False then the IF statement evaluates to null. Since COUNTD() silently ignores nulls, like other aggregation functions, the expression acts as if the irrelevant data rows were filtered.
So, for example,
COUNTD(IF [dates] >= #2/16/2020# AND [dates] <= #3/16/2020# THEN [user_code] END)
Will tell you then number of unique user codes during the period between 2/16 and 3/16. The DateDiff() function will probably be useful in more elaborate tests.
Finally, what if you want more flexibility? You could easily use Parameters or Filter controls to let the user choose the date range interactively.
If you want this calculation repeated for each possible day, showing the unique users in the preceding 30 day period, as some sort of rolling calculation, then you’ll need to learn about some more advanced features. Either multiple calculations as above for different time ranges, using Table Calculations, or some data prep and/or data padding with Tableau Prep Builder, Python or some other technique — mostly because in that scenario each data row contributes to multiple rolling counts, rather than one count when partitioning the data by some dimension.

Getting a percentage in Tableau from a yes/no column

I have a spreadsheet of support case management data. I am working with this in Tableau. Each line in the spreadsheet is an individual case. Each case has, among much else, a support agent name and a Yes or No of whether the case work was started within 12 hours. I'd like to know, for each agent, what percentage of the time they started the case work within 12 hours. So, if Bob has 2 "No" and 8 "Yes", he should have 8 / (2 + 8) = 80%.
My attempt at this was to create 2 sets. One is the set of "Yes, started within 12 hours" (those that have "yes" in that field, and one that is the set of "No, not started within 12 hours", the complement to the other set. Silly me, I thought I could do something like COUNT(yeses) / COUNT(nos). Nope, big red failure. So what is the right way to do this?
It would help immensely to please respond as if this is the first thing I have ever done in Tableau. It is. I have learned a lot in this project, but only in comparison to the nothing I knew previously. Please also let me know if I've left out something necessary to answer this. I've tried to be complete but, well, am noob...
If it clarifies anything, here's a poor Excel mockup of data and the effect I'm looking for:
Yes, this is possible and easy in Tableau, but first a couple of points.
The reason your attempt to use COUNT() did not work is that COUNT() does not operate the way you, and that 99% of the people on the planet, expect. COUNT([some expression]) returns the number of records that have a non-null value, any value, for [some expression]. The name comes from SQL relational databases.
The calculations would be just a bit simpler if your third column took the boolean values True or False instead of the string values “Yes” or “No”. (In which case you could drop ‘= “Yes”’ from the formula below)
So two ways to do your calculation are:
Directly with an aggregate calculation which can get the right result, but is hard coded for this case, such as:
SUM(INT([Started within 24 hrs?] = “Yes”)) / SUM([Number of Records])
Using a table calc - which in this case is a bit easier and more flexible.
First, Build a table or viz in Tableau showing SUM([Number of Records]) with the dimensions you care about in play. Say with [Name] on Rows, [Started within 24 hrs?] on Columns and SUM([Number of Records] on Text. Second, Right click on your measure SUM([Number of Records]) and choose Percentage of Total from the Quick Table Calc menu. Finally, use that same menu to adjust Compute Using to specify how you want the percentages computed - in this case, using [Started within 24 hrs?]
If you only want to show some of the data, right click on the column header for the values you wish to hide and choose Hide.
The type conversion function INT() converts True to 1 and False to 0.
You could create another column that converts the Yes's into 1's, and the No's into 0's. Sum up all the 1's and divide it by the total and that's your percentage.
edit: the new column would look something like
=IF(C3="Yes",1,0)
in other words, if Cⁿ is "Yes", then 1, else 0

Count # of records by grouped date?

I'm a novice Tableau user, trying to help my organization to analyze phone traffic. My data source of incoming phone calls is in an Excel spreadsheet, and is listed like this:
TRANSACTION ID DATETIME
151313:179805 1/2/2018 9:57
151340:108017 1/2/2018 17:27
151395:176211 1/3/2018 15:27
Our total calls per day range from 10 to 50.
I'd like to count days with an identical # of calls, and probably make a Histogram sorted by # of calls on the X-Axis, and # of days w/ that many calls on the Y-Axis.
I feel like this would be a simple Calculated Field, but for the life of me, I'm not getting what I'd do here.
Help! :)
One solution is to define an LOD calc, calls_per_day, as
{ FIXED DateTrunc('day', [DATETIME]) : COUNT("*") }
which in effect, prebuilds a little table in space showing the number of data rows for each day. That works if you have one data row in your input per transaction id.
If transaction ids are repeated, and instead you want the number of transactions for each day, you can use the following variation.
{ FIXED DateTrunc('day', [DATETIME]) : COUNTD([TRANSACTION ID]) }
COUNTD() can be expensive on large data sets, so its better to use an alternative when you have the option.
You can use LoD
{Fixed TRANSACTION ID : Count(Day(DATETIME))}
Try this and post the result

Tableau Future and Current References

Tough problem I am working on here.
I have a table of CustomerIDs and CallDates. I want to measure whether there is a 'repeat call' within a certain period of time (up to 30 days).
I plan on creating a parameter called RepeatTime which is a range from 0 - 30 days, so the user can slide a scale to see the number/percentage of total repeats.
In Excel, I have this working. I sort CustomerID in order and then sort CallDate from earliest to latest. I then have formulas like:
=IF(AND(CurrentCustomerID = FutureCustomerID, FutureCallDate - CurrentCallDate <= RepeatTime), 1,0)
CurrentCustomerID = the current row, and the FutureCustomerID = the following row (so it is saying if the customer ID is the same).
FutureCallDate = the following row and the CurrentCallDate = the current row. It is subtracting the future call time from the first call time to measure the time in between.
The goal is to be able to see, dynamically, how many customers called in for a specific reason within maybe 4 hours or 1 day or 5 days, etc. All of the way up until 30 days (this is our actual metric but it is good to see the calls which are repeats within a shorter time frame so we can investigate).
I had a similar problem, see here for detailed version Array calculation in Tableau, maxif routine
In your case, that is basically the same thing as mine, so you could apply that solution, but I find it easier to understand the one I'm about to give, I would do:
1) Create a calculated field called RepeatTime:
DATEDIFF('day',MAX(CallDates),LOOKUP(MAX(CallDates),-1))
This will calculated how many days have passed since the last call to the current. You can add a IFNULL not to get Null values for the first entry.
2) Drag CustomersID, CallDates and RepeatTime to the worksheet (can be on the marks tab, don't need to be on rows or column).
3) Configure the table calculation of RepeatTIme, Compute using Advanced..., partitioning CustomersID, Adressing CallDates
Also Sort by Field CallDates, Maximum, Ascending.
This will guarantee the table calculation works properly
4) Now you have a base that you can use for what you need. You can either export it to csv or mdb and connect to it.
The best approach, actually, is to have this RepeatTime field calculated outside Tableau, on your database, so it's already there when you connect to it. But this is a way to use Tableau to do the calculation for you.
Unfortunately there's no direct way to do this directly with your database.

Default range for date range filter in tableau

I want to set the default range on a date filter to show me the last 10 days - so basically looking at the lastDate (max date) in the data and default filtering only on the last 10 days (maxDate - 10)
How it looks now:
I still would want to the see the entire range bar on the dashboard and give the user the ability to modify the selected range if he wants to. The maxDate changes after every data refresh so it has to be some sort of a condition that is applied to the filter.
How I want it to look (by default after every refresh of data - new dates coming in):
Any suggestions on how this can be done? I know I can use the relative date and show the data for last 10 days but that would modify the filter and create a drop down which I don't want.
Any suggestions are welcome!
One simple approach that does most of what you want is the following:
Create an integer valued parameter with a range from 1 to some max
you choose, say 100. Call it say num_days.
Show the parameter control on your dashboard as a slider, and give
it a nice title like "Number of days to display"
Create a boolean calculated field called Within_Day_Range defined as:
datediff('minute', [My_Date_Field], now()) < [num_days] * 24 * 60
Put Within_Day_Range on the filter shelf and select the value true.
This lets the user easily select how many days in the past to include, and works to the granularity of minutes (i.e. the last two days really means the last 48 hours, not starting at midnight yesterday). Adjust the calculated field if you want different behavior.
The main drawback of this approach as described so far is that it doesn't display the earliest date possible in the database because that is filtered out. Quick filters do an initial query to get the bounds, which has a performance cost -- so using the approach described here can avoid that query and thus load faster.
If you really need that information on your dashboard, you could create a different worksheet to get just the min([My_Date_Field]) and display that near your parameter control.