Performance troubleshooting, where are my bottlenecks?

[BrianHFASPS]

I am trying to optimize my users experience and I am not sure how to troubleshoot performance of my app. My biggest pain point is when users do a bunch of Patch to a Azure SQL DB. I am reading values from a local collection and then creating records in a table via patch. Sometimes I am lucky and it does 4 per second, sometimes I am unlucky and it is 4 seconds per record. Also the fact that it is really inconsistent is frustrating for users. Here is me prime offender code. It is usually acting upon a list of 10-15 rows. The second ForAll in the If is the thing that takes the most time. After the code is a shot of the table that includes time.

UpdateContext({LCVisible: false});
If(
    'Attendance Class Name Dropdown'.Selected.Activity_x0020_Name = "Garderie after Activity",
    ForAll(
        Roster,
        Patch(
            '[dbo].[Daily Activity Attendance]',
            LookUp(
                '[dbo].[Daily Activity Attendance]',
                DailyAttUID = User_x0020_ID && 'AttendanceDate String' = TodayVar
            ),
            {
                ActivityTwo: 'Attendance Class Name Dropdown'.Selected.ActivityID,
                ActivityTwoSigninTime: Text(
                    Now(),
                    "[$-en-US]hh:mm:ss"
                )
            }
        )
    ),
    ForAll(
        Roster,
        If(
            IsBlank(
                LookUp(
                    '[dbo].[Daily Activity Attendance]',
                    DailyAttUID = User_x0020_ID && 'AttendanceDate String' = TodayVar
                )
            ),
            Patch(
                '[dbo].[Daily Activity Attendance]',
                Defaults('[dbo].[Daily Activity Attendance]'),
                {
                    DailyAttUID: User_x0020_ID,
                    AttendanceDate: Today(),
                    ActivityOne: 'Attendance Class Name Dropdown'.Selected.ActivityID,
                    ActivityOneSigninTime: Text(
                        Now(),
                        "[$-en-US]hh:mm:ss"
                    )
                }
            ),
            Patch(
                '[dbo].[Daily Activity Attendance]',
                LookUp(
                    '[dbo].[Daily Activity Attendance]',
                    DailyAttUID = User_x0020_ID && 'AttendanceDate String' = TodayVar
                ),
                {
                    ActivityOneSigninTime: Text(
                        Now(),
                        "[$-en-US]hh:mm:ss"
                    )
                }
            )
        )
    );
    ForAll(
        AbsentList,
        If(
            IsBlank(
                LookUp(
                    '[dbo].[Daily Activity Attendance]',
                    DailyAttUID = User_x0020_ID && 'AttendanceDate String' = TodayVar
                )
            ),
            Patch(
                '[dbo].[Daily Activity Attendance]',
                Defaults('[dbo].[Daily Activity Attendance]'),
                {
                    DailyAttUID: User_x0020_ID,
                    AttendanceDate: Today(),
                    ActivityOne: 'Attendance Class Name Dropdown'.Selected.ActivityID,
                    Absent: 1
                }
            ),
            Patch(
                '[dbo].[Daily Activity Attendance]',
                LookUp(
                    '[dbo].[Daily Activity Attendance]',
                    DailyAttUID = User_x0020_ID && 'AttendanceDate String' = TodayVar
                ),
                {Absent: 1}
            )
        )
    )
);
Patch(
    '[dbo].[Activities]',
    LookUp(
        '[dbo].[Activities]',
        ActivityID = 'Attendance Class Name Dropdown'.Selected.ActivityID
    ),
    {AttTakenDate: Today()}
);
Refresh('[dbo].[Activities]');
Refresh('[dbo].[Activity View]');
Clear(ClassList);
Clear(AbsentList);
Clear(Roster);
UpdateContext({LCVisible: true})

Any suggestions on finding and fixing my bottleneck or just trying to trace performance issues. I can do this on a wired desktop with GB ethernet to fiber connection with less than 25 ms ping to powerapps.com. I don't think it is my network but I am open to help on that. The quantity of data is tiny we are talking KB of data.

Brian Hoyt

[RandyHayes]

@BrianHFASPS 

You might want to refactor it a little.  You are looking up the records for your patch statements over and over.  Normally not a big issue, but that could be refactored a bit.

Perhaps consider using an UpdateIf rather than a Patch for records that do exist.

Just some thoughts...perhaps it will spark some help.

[Jinman]

BrianHFASPS, can you share AppId or SessionId? will check telemetry to see which layers caused such bottleneck.

[BrianHFASPS]

---

@Jinman wrote:

BrianHFASPS, can you share AppId or SessionId? will check telemetry to see which layers caused such bottleneck.

---

Can I get that for past use or should I run a test and grab id?

[BrianHFASPS]

---

@Jinman wrote:

BrianHFASPS, can you share AppId or SessionId? will check telemetry to see which layers caused such bottleneck.

---

Did a quick test and it was quicker than it often is this morning. 

Session ID: a4996443-d572-4b4e-a874-6c3735252fd2
PowerApps 3.19031.13

App ID

d133c35b-f219-4afc-a10a-3019be297766

Thanks for any help you can provide. I will grab session ID for real runthrough this afternoon.

[Jinman]

Thanks for sharing AppId. checked telemetry and couldn't find any bottleneck on Patching procedures.

From your app, the worst patching request had taken 696 ms in server side within last 24hours. 

If you encounter slowness of Patching again, please let me know with time window and sessionId.

However, I noticed that retrieving 500 records from Daily Activity Attendance takes up to 00 sec with transmitting 35 MBytes of data size. Both transmitting and scripting time for that request is high.

Could you select only necessary columns to retrieve? or you can create a View returning only necessary columns and use the view for Daily Activity Attendance.

Another point is to check if following tables have indexes.

1. [Today Absent XXXX] should have an index on Student_x0020_Last_x0020_Name Asc

2. [Bus Routes YYYY] table should have an index on Time Asc

3. [Activities ZZZZ] table should hvave an index on ActivityId Asc

[BrianHFASPS]

---

@Jinman wrote:

Thanks for sharing AppId. checked telemetry and couldn't find any bottleneck on Patching procedures.

From your app, the worst patching request had taken 696 ms in server side within last 24hours. 

If you encounter slowness of Patching again, please let me know with time window and sessionId.

However, I noticed that retrieving 500 records from Daily Activity Attendance takes up to 00 sec with transmitting 35 MBytes of data size. Both transmitting and scripting time for that request is high.

Could you select only necessary columns to retrieve? or you can create a View returning only necessary columns and use the view for Daily Activity Attendance.

Another point is to check if following tables have indexes.

1. [Today Absent XXXX] should have an index on Student_x0020_Last_x0020_Name Asc

2. [Bus Routes YYYY] table should have an index on Time Asc

3. [Activities ZZZZ] table should hvave an index on ActivityId Asc

---

I am pretty new to PowerApps (and not very knowledgable on SQL perf tuning) so thanks for the pointers here. Is the big data transfer caused when I do a Refresh on that table or would it also be caused on a LookUp? I am not sure where I am causing that big lookup. To your point however I have created a view that exculdes the two photo / binary columns and also limits the rows to relevant ones to hopefully greatly shrink that query. 

I am now reading about how to create indexs on tables and views (again new to SQL perf). This is the first DB I have created, I am usually mucking around in someone elses.

[BrianHFASPS]

---

@BrianHFASPS wrote:

---

I am now reading about how to create indexs on tables and views (again new to SQL perf). This is the first DB I have created, I am usually mucking around in someone elses.

---

If you wouldn't mind could you help me verify this is what you were recommending doing to create indexes?

CREATE INDEX idx_ActivityID
ON dbo.Activities (ActivityID ASC)

CREATE INDEX idx_Time
ON [dbo].[Bus Routes] (Time ASC)

I tried to add index to my view. I added SCHEMABINDING first but then it failed because I use Outer Joins. May have to refactor my view to get it to work.

[BrianHFASPS]

Ok I refactored my View and got to all be inner joins (that was a good exercise I will do on other views now that my DB and data have matured) but it now complains "The function 'getdate' yields nondeterministic results. Use a deterministic system function, or modify the user-defined function to return deterministic results." The problem is the entire purpose of this view and several others I use is to narrow my daily attendance table to only be today's attendance. The hope being to shrink the data size that gets fed to App to be smaller than 200 rows or an ever growing table.

[Jinman]

Thanks BrianHFASPS. You are catching very fast.

Yes, the given syntax is correct to create index.

CREATE INDEX idx_Time
ON [dbo].[Bus Routes] (Time ASC)

In general, we recommend to have WITH ( ONLINE=ON ) option always, which allows any transactions be executing while this index get creating. it would be great if you explicitly mention NONCLUSTERED word too. 

CREATE NONCLUSTERED INDEX idx_Time ON [dbo].[Bus Routes] (Time ASC) WITH(ONLINE=ON)

If you made changes, can you do test once again? Let's do compare to see if these activities improved the performance of your app and also to see what next comes up.