Missing chunk of snap data of (800m) using *Match* service of OSRM

[jawwadmalik]

In one of our tracking application I'm using OSRM's Match service to snap roads over google-map by using the tracking device data. During that snapping there are multiple data chunks missing. Following is the scenario:

• I fetch data from backend for specific time-period and device
• Then I remove duplicate latlng from that data and make multiple API URL's of around 100 latlngs with base match service API slug and call these APIs concurrently with 20m of radius for each latlng point with timestamps.
• On successfull response from each API, I made a list of latlngs from geometry response from OSRM API.
• After making that list I pass that array of latlngs to google-map to draw a polyline based on this data.
• Here's a problem I am facing of missing data chunk.
• I create a start-point marker baseed on the 1st location from my backend API (Raw data)
• Polyline which is created, its starting point is different from that start-point marker
• There is a distance between these two points of around 800 meters which is not acceptable in my tracking application.

I debugged this issue throughly and compare the responses from backend API and OSRM API and found that the starting 800m distance of polyline data is missing from OSRM's API.

match/v1/driving/51.2760766,25.48607;51.276075,25.4861216;51.2761133,25.4860666;51.2761216,25.4860599;51.27641,25.4861466;51.2764633,25.48615;51.2766983,25.4861416;51.2767349,25.4861316;51.2770216,25.48634;51.2771066,25.4864633;51.2771916,25.4864316;51.27735,25.486685;51.2772999,25.4868016;51.2772866,25.4868216;51.27728,25.4868183;51.2772716,25.4868166;51.2772266,25.4868;51.2772166,25.4868116;51.2772116,25.4867966;51.2772516,25.4867949;51.2772749,25.486815;51.2772233,25.4867599;51.2772333,25.4867683;51.2772283,25.4867733;51.2772233,25.4867199;51.277215,25.4867766;51.2772633,25.4867349;51.2772999,25.4867533;51.2772433,25.4868416;51.2769783,25.486875;51.2767216,25.4868766;51.2764466,25.4868883;51.276345,25.4866116;51.2764133,25.4863183;51.276345,25.4860533;51.2757,25.4859266;51.275585,25.485545;51.2754133,25.4851583;51.2752216,25.4847233;51.2750833,25.4842533;51.2749333,25.4838066;51.2748249,25.483365;51.2747966,25.4828966;51.2747166,25.482405;51.2747566,25.4819466;51.2751566,25.4816383;51.2755883,25.4814983;51.2760099,25.4814583;51.2770966,25.481175;51.2776049,25.4810833;51.2781016,25.4809549;51.2786866,25.4808383;51.2792766,25.4806749;51.2798833,25.48046;51.2805049,25.48034;51.2809816,25.480255;51.2814599,25.48013;51.2819966,25.4799799;51.2825416,25.4798716;51.2830233,25.4797316;51.2834866,25.479595;51.2840066,25.4794483;51.2844916,25.479285;51.2849283,25.479115;51.2854266,25.4789416;51.2859016,25.4787816;51.2863299,25.4786016;51.2867583,25.4784799;51.2870716,25.4783833;51.2872433,25.4782766;51.2873266,25.4782399;51.2880483,25.4787483;51.288685,25.4792616;51.2895799,25.4799733;51.2908533,25.4808;51.2922116,25.48163;51.2937549,25.4824216;51.2975066,25.4839616;51.3016999,25.4855649;51.303995,25.4864483;51.3062233,25.4873333;51.308475,25.4881983;51.3107183,25.4890866;51.312945,25.489935;51.3152133,25.4908233;51.3174666,25.4917033;51.3195383,25.4924933;51.3214166,25.4932399;51.3246916,25.4945366;51.3263583,25.4951599;51.3280099,25.4957799;51.3292866,25.49627;51.3299083,25.49653;51.330135,25.4966433;51.3303566,25.4964666;51.3306233,25.4960499;51.3310866,25.495415;51.3316533,25.4946249;51.332405,25.4935983?timestamps=1746078311;1746078489;1746078495;1746078496;1746078527;1746078537;1746078547;1746078550;1746078564;1746078571;1746078576;1746078590;1746078614;1746078617;1746078626;1746078630;1746078650;1746078653;1746078662;1746078679;1746078687;1746078713;1746078717;1746078723;1746078752;1746078758;1746078768;1746078807;1746078825;1746078835;1746078845;1746078855;1746078865;1746078875;1746078885;1746078905;1746078915;1746078925;1746078935;1746078945;1746078955;1746078965;1746078975;1746078985;1746078995;1746079005;1746079015;1746079025;1746079045;1746079055;1746079065;1746079075;1746079085;1746079095;1746079105;1746079115;1746079125;1746079135;1746079145;1746079155;1746079165;1746079175;1746079185;1746079195;1746079205;1746079215;1746079225;1746079235;1746079245;1746079255;1746079260;1746079280;1746079290;1746079300;1746079310;1746079320;1746079330;1746079350;1746079370;1746079380;1746079390;1746079400;1746079410;1746079420;1746079430;1746079440;1746079450;1746079460;1746079480;1746079490;1746079500;1746079509;1746079519;1746079529;1746079539;1746079549;1746079559;1746079569;1746079579&radiuses=20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20;20&overview=full&geometries=geojson

This is the API request I'm making, and is response of this API I found that missing data chunk.

So, I need some support to fix this issue for my tracking application.

[DennisOSRM]

Not sure I fully understand the issue. Could you provide screenshots explaining the issue?

[jawwadmalik]

Yes sure. I'm attaching the screenshot, for what I'm facing.

In this picture over google-map, on top side blue-color marker filled with purple color circle is showing the actual start-location of device.
And start of green-colored polyline is far from this point. Here you can see there is the gap between that start-location marker and start point of polyline, which is causing problem for me, becuase when i debugged these two points directly over google-map by placing both points, i found that there is a gap between these points of 800 meters. 10 or 20m distance gap is acceptable but 800 is not.

Best regards.