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# Availability on OMS

Hi everyone.

I'm trying to find a way of getting Availability of servers on OMS, but I can't find any...

By Availability I mean the % of uptime of a given server during a certain period of time.

So, if a server was up 98 of a total 100 hours, the availability for that period is 98%.

I'm looking to do that in OMS, but I'm not sure it's possible.

27 Replies

# Re: Availability on OMS

Hi There is no out of the box solution for this. Probably one way to calculate this is by using Heartbeat events. For Windows machines they are logged every 1 minute and for Linux every 5 minutes. You could probably calculate what should be the sum of the events for each machine and also the maximum sum for specific time frame. From those two values you can calculate the percentage. The query language is pretty rich so this should be possible.

# Re: Availability on OMS

Stanislav is right, it's possible :)

Here's an example that calculates the availability rate of each computer, starting at midnight.

```let midnight=startofday(now());
Heartbeat
| where TimeGenerated>midnight
| summarize heartbeat_per_hour=count() by bin_at(TimeGenerated, 1h, midnight), Computer
| extend available_per_hour=iff(heartbeat_per_hour>0, true, false)
| summarize total_available_hours=countif(available_per_hour==true) by Computer
| extend number_of_buckets=hourofday(now())+1
| extend availability_rate=total_available_hours*100/number_of_buckets```

Run it on our playground and tweak it as makes sense to you.

# Re: Availability on OMS

Thank you for your help, im going to investigate a bit that query.

However, i'm not sure about that approach because the heartbeat happens to stop working a lot even if the VM is perfectly fine.

But I understand the approach...

# Re: Availability on OMS

Heartbeat should be running without issue however there are scenarios when you might not get data: - Log Analytics service is down - You machine has lost Internet connection - MMA agent service is stopped - MMA agent is not functioning properly

# Re: Availability on OMS

The last situation MMA agent not working properly or has stopped working is exactly what worries me in order to create the availability report based on heartbeats.

# Re: Availability on OMS

Noa, your script is amazing, however i'm struggling to understand it and tweak it to my needs (30 fixed days, for example from 1st to 31 of january)

Could you gimme a hand to understand it?

```let midnight=startofday(now()) ; #First part. I need to change this to between((2018-01-01) .. (2017-01-31)); am I correct?
Heartbeat
| where TimeGenerated>midnight
| summarize heartbeat_per_hour=count() by bin_at(TimeGenerated, 1h, midnight) #im not sure i understand why do you use bin_at instead of just bin, Computer
| extend available_per_hour=iff(heartbeat_per_hour>0, true, false)
| summarize total_available_hours=countif(available_per_hour==true) by Computer
| extend number_of_buckets=hourofday(now())+1
| extend availability_rate=total_available_hours*100/number_of_buckets```

Solution

# Re: Availability on OMS

Sure. I tweaked it a bit to match what you ask for:

```let start_time=startofday(datetime("2017-01-01"));
let end_time=endofday(datetime("2017-01-31"));
Heartbeat
| where TimeGenerated > start_time and TimeGenerated < end_time
| summarize heartbeat_per_hour=count() by bin_at(TimeGenerated, 1h, start_time), Computer
| extend available_per_hour=iff(heartbeat_per_hour>0, true, false)
| summarize total_available_hours=countif(available_per_hour==true) by Computer
| extend total_number_of_buckets=round((end_time-start_time)/1h)
| extend availability_rate=total_available_hours*100/total_number_of_buckets```

The first 2 lines define variables, set to the start and end time you mentioned.

Next, we use these variables to limit the query to that time range:

`| where TimeGenerated > start_time and TimeGenerated < end_time`

Then we count the heartbeats reported from each computer, in buckets (bins) of 1 hour, starting at the start time you define:

`| summarize heartbeat_per_hour=count() by bin_at(TimeGenerated, 1h, start_time), Computer`

Now we can see how many heartbeats were reported by each computer each hour. If the number is  0 we understand the computer was probably offline at that time.

We use a new column to mark if a computer was available or not each hour:

`| extend available_per_hour=iff(heartbeat_per_hour>0, true, false)`

and then count the number of hours each computer was indeed "alive":

`| summarize total_available_hours=countif(available_per_hour==true) by Computer`

Note that this way we give a little leeway for missing heartbeat reports each hour. Instead of expecting a report every 5 or 10 minutes, we only mark a computer as "unavailable" if we didn't get any report from it during a full hour.

At this point we get a number for each computer, something like this:

So we know each computer was alive 11 hours in the select time range. But what does it mean? how many hours were there altogether? is this 11 out of 11 hours (100% availability) or out of 110 hours (only 10% availability)?

Here's how we can calculate the total number of hours in the selected time range:

`| extend total_number_of_buckets=round((end_time-start_time)/1h)+1`

I admit it might not be the best calculation of buckets.. there is probably a better way but I can't think of it now..

finally we calculate the ratio between available hours and total hours:

`| extend availability_rate=total_available_hours*100/total_number_of_buckets`

and get this:

HTH,

Noa

# Re: Availability on OMS

Noa, amazing, thank you so much.

# Re: Availability on OMS

Excellent query. How can "let midnight=startofday(now())" be altered to make it my local time zone? If I run this as is, it seems to be my time +7, and the amount of hours don't match up.

# Re: Availability on OMS

Hi,

Thanks for a exellent code sample.

I would like to extend the Query, supporting also specified time intervals and smaller uptime checks (heartbeat)

# Service levels

Ex: Service agreements are based on 3 categories

S1 = 07:00 - 17:00 Weekdays

S2 = 07:00- 22:00 Weekdays

= Uptime should be calculated based on service agreement hours/days

Time should also be converted to UTC +1

- will this do the trick = >

Heartbeat
| extend Timegenerated = TimeGenerated + 1h

I checked the samples from endofday/week, but are unable to get it to work in your sample

# Intervals
extend available_per_hour=iff(heartbeat_per_hour>0, true, false)
= can this be adjusted to heartbeat per 30 min / 15 min

Any ideas ?

Br
erik

# Re: Availability on OMS

Thanks George.

To adjust for the local time zone you can do this:

`let midnight=startofday(now())-7h`

# Re: Availability on OMS

Hi Eric,

To adjust for the service agreement, you can calculate the start time and end time like this:

```let raw_date = datetime("2017-01-01");
let start_date = case("SLA" in ("S1", "S2"), case(dayofweek(raw_date)==0, startofday(raw_date+1d)+7h,
dayofweek(raw_date)==6, startofday(raw_date+2d)+7h,
startofday(raw_date)+7h),
raw_date);```

On the intervals - it can adjusted any way you need, just use `bin(fieldname, 30m)` instead of `bin(fieldname, 1h)`.

# Re: Availability on OMS

it is a pwerShell Script?

# Re: Availability on OMS

Hey,

That's not powershell but our query language, that can be used here and through our API.

# Re: Availability on OMS

I am struggling to generate the report for Mon-Friday only and in my time zone. I just get errors.

let start_time=startofday(datetime("2018-07-1 07:30:00"));
let end_time=endofday(datetime("2018-07-31 18:00:00"));
Heartbeat
| where TimeGenerated > start_time and TimeGenerated < end_time
| summarize heartbeat_per_hour=count() by bin_at(TimeGenerated, 1h, start_time), Computer
| extend available_per_hour=iff(heartbeat_per_hour>0, true, false)
| summarize total_available_hours=countif(available_per_hour==true) by Computer
| extend total_number_of_buckets=round((end_time-start_time)/1h)
| extend availability_rate=total_available_hours*100/total_number_of_buckets

# Re: Availability on OMS

I am struggling to generate the report for Mon-Friday only and in my time zone. I just get errors. The script below works for me. Thanks

let start_time=startofday(datetime("2018-07-1 07:30:00"));
let end_time=endofday(datetime("2018-07-31 18:00:00"));
Heartbeat
| where TimeGenerated > start_time and TimeGenerated < end_time
| summarize heartbeat_per_hour=count() by bin_at(TimeGenerated, 1h, start_time), Computer
| extend available_per_hour=iff(heartbeat_per_hour>0, true, false)
| summarize total_available_hours=countif(available_per_hour==true) by Computer
| extend total_number_of_buckets=round((end_time-start_time)/1h)
| extend availability_rate=total_available_hours*100/total_number_of_buckets

# Re: Availability on OMS

Hey Noa,

Can we take the 1 year details by this script.?

# Re: Availability on OMS

Can  we Availabilty for past 10 days instead of add start date and End date

# Re: Availability on OMS

Thanks but I got the answer

let month = startofday(ago(3d));
Heartbeat
| where TimeGenerated>ago(3d)
| summarize heartbeat_per_hour=count() by bin_at(TimeGenerated, 1h, (ago(3d))), Computer
| extend available_per_hour=iff(heartbeat_per_hour>0, true, false)
| summarize total_available_hours=countif(available_per_hour==true) by Computer
| extend total_number_of_buckets= round((now()-month)/1h)-2
| extend availability_rate=total_available_hours*100/total_number_of_buckets

# Re: Availability on OMS

Hi Prashant,

We can get data by doing amendment in dates. But make sure you have data retention policy for last year to save data.

You can check here:-

Hi Gaurav,

I got it,

Thank You

# Re: Availability on OMS

Love this query. I'm having trouble modifying it to meet my needs.

In addition to what this query provides, I'd also like to show the last TimeGenerated for each Computer. I can't seem to get the logic to work correctly. Any help is appreciated.

# Re: Availability on OMS

let start_time=startofday(ago(30d));
let end_time=startofday(now());
Heartbeat
| where TimeGenerated > start_time and TimeGenerated < end_time
| summarize heartbeat_per_hour=count() by bin_at(TimeGenerated, 1h, start_time), Computer
| extend available_per_hour=iff(heartbeat_per_hour>0, true, false)
| summarize total_available_hours=countif(available_per_hour==true) by Computer
| extend total_number_of_buckets=round((end_time-start_time)/1h)
| extend availability_rate=total_available_hours*100/total_number_of_buckets
| order by availability_rate desc

# Re: Availability on OMS

Awesome Script Thanks

# Re: Availability on OMS

Does anyone have a way to restrict the script to pull heartbeats Mon-Fri and 7am-6pm? I keep getting errors. This is what I have:

let start_time=startofday(datetime("2018-06-1 07:30:00"));
let end_time=endofday(datetime("2018-06-30 18:00:00"));
Heartbeat
| where TimeGenerated > start_time and TimeGenerated < end_time
| summarize heartbeat_per_hour=count() by bin_at(TimeGenerated, 1h, start_time), Computer
| extend available_per_hour=iff(heartbeat_per_hour>0, true, false)
| summarize total_available_hours=countif(available_per_hour==true) by Computer
| extend total_number_of_buckets=round((end_time-start_time)/1h)
| extend availability_rate=total_available_hours*100/total_number_of_buckets

# Re: Availability on OMS

I have used the query, there are some differences which is not reflecting for us in the log analytics.

We are doing the Monthly patches for the Virtual Machines.So when i tried this query it is showing the availability rate as 100% percentage.
But we are rebooting the server after the patching activity, the Availability report percentage should differ but it is showing 100% percent for all the servers.

Can anyone help us on this ? how can we get the exact report ?

# Re: Availability on OMS

Hi! I've update the above query to reflect your week days and hours (Mon-Fri, 07:00-17:59).

Also, the above query considers every hour in which there was even 1 heartbeat as "up time" (available), so this is probably the part you want to tweak. The resolution here depends on your agent. If it reports a heartbeat every 5 minutes, you can do this:

``````let start_time=startofday(datetime("2019-08-01 07:00:00"));
let end_time=endofday(datetime("2019-08-30 18:00:00"));
Heartbeat
| where TimeGenerated >= start_time and TimeGenerated <= end_time
| where dayofweek(TimeGenerated) >= 1d and dayofweek(TimeGenerated) <= 5d  // Monday-Friday
| where hourofday(TimeGenerated) >= 7 and hourofday(TimeGenerated) <=17   // 7:00-17:59
| summarize heartbeat_per_5_minutes=count() by bin_at(TimeGenerated, 5m, start_time), Computer
| extend available_per_5_min=iff(heartbeat_per_5_minutes>0, true, false)
| summarize total_available_buckets=countif(available_per_5_min==true)
, total_unavailable_buckets=countif(available_per_5_min==false) by Computer
| extend total_number_of_buckets=round(total_available_buckets+total_unavailable_buckets)
| extend availability_rate=total_available_buckets*100/total_number_of_buckets``````

Note than anyway, if the reboot was quick and the agent sends a heartbeat every 5 minutes, it might go unnoticed.

HTH,

Noa