umcompressed pdb can not be retrieved from symbol server #2432

tonghao-bbl · 2026-06-02T03:35:13Z

tonghao-bbl
Jun 2, 2026

Hi I got a http code 406 saying not accpeted for uncompredded pdbs from a private symbol server.
seems this line forces a msfz0 format?

perfview/src/TraceEvent/Symbols/SymbolReader.cs

Line 1322 in 422494e

request.Headers.Add("Accept", "application/msfz0");

Answered by brianrob

Jun 2, 2026

This line tells the symbol server that the client is capable of accepting msfz0 symbols - see https://github.com/microsoft/pdb-rs/blob/main/docs/pdb/msfz.md for the spec.

I suspect this is a bug in the symbol server itself. Is this a Microsoft symbol server?

View full answer

tonghao-bbl · 2026-06-02T03:47:29Z

tonghao-bbl
Jun 2, 2026
Author

the full http stream captured by wireshark with host and pdb name stripped:

GET /XXXXX.pdb/3DA5F03F1FCF47578023C1ED7F5910FB2/XXXXX.pdb HTTP/1.1
Accept: application/msfz0
User-Agent: Microsoft-Symbol-Server/6.13.0009.1140
Host: my-private-symbol-server:8088
Connection: Keep-Alive


HTTP/1.1 406 Not Acceptable
Content-Type: text/html
Server: Microsoft-IIS/10.0
Date: Tue, 02 Jun 2026 03:44:55 GMT
Content-Length: 1315

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312"/>
<title>406 - .................. MIME ................</title>
<style type="text/css">
<!--
body{margin:0;font-size:.7em;font-family:Verdana, Arial, Helvetica, sans-serif;background:#EEEEEE;}
fieldset{padding:0 15px 10px 15px;} 
h1{font-size:2.4em;margin:0;color:#FFF;}
h2{font-size:1.7em;margin:0;color:#CC0000;} 
h3{font-size:1.2em;margin:10px 0 0 0;color:#000000;} 
#header{width:96%;margin:0 0 0 0;padding:6px 2% 6px 2%;font-family:"trebuchet MS", Verdana, sans-serif;color:#FFF;
background-color:#555555;}
#content{margin:0 0 0 2%;position:relative;}
.content-container{background:#FFF;width:96%;margin-top:8px;padding:10px;position:relative;}
-->
</style>
</head>
<body>
<div id="header"><h1>Server Error</h1></div>
<div id="content">
 <div class="content-container"><fieldset>
  <h2>406 - Client browser does not accept the MIME type of the requested page.</h2>
  <h3>The page you are looking for cannot be opened by your browser because it has a file name extension that your browser does not accept.</h3>
 </fieldset></div>
</div>
</body>
</html>

0 replies

tonghao-bbl · 2026-06-02T03:57:19Z

tonghao-bbl
Jun 2, 2026
Author

the version just before this commit 3.1.22 works fine

GET /XXXXX.pdb/3DA5F03F1FCF47578023C1ED7F5910FB2/XXXXX.pdb HTTP/1.1
User-Agent: Microsoft-Symbol-Server/6.13.0009.1140
Host: my-private-symbol-server:8088
Connection: Keep-Alive


HTTP/1.1 200 OK
Content-Type: application/octet-stream
Last-Modified: Thu, 14 May 2026 10:03:25 GMT
Accept-Ranges: bytes
ETag: "d2f072e788e3dc1:0"
Server: Microsoft-IIS/10.0
Date: Tue, 02 Jun 2026 03:50:14 GMT
Content-Length: 1140420608

Microsoft C/C++ MSF 7.00

0 replies

brianrob · 2026-06-02T19:36:02Z

brianrob
Jun 2, 2026
Maintainer

This line tells the symbol server that the client is capable of accepting msfz0 symbols - see https://github.com/microsoft/pdb-rs/blob/main/docs/pdb/msfz.md for the spec.

I suspect this is a bug in the symbol server itself. Is this a Microsoft symbol server?

1 reply

tonghao-bbl Jun 19, 2026
Author

Yes, its a MS symbol server. we fix this issue by changing the behaviour of the server.

Thanks!

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