cache_disk:error AH00708: Cannot open .data file, possible race condition
[email protected] (Unknown) Mon, 27 Apr 2026 17:18:09 +0000
| Newsgroups | gmane.comp.apache.user |
|---|---|
| Message-ID | <MN2PR09MB60106941AE0F1CAAB3C53EEED3362@MN2PR09MB6010.namprd09.prod.outlook.com> |
From: "Llewellyn, Grace (US 342C) via users" <[email protected]> Reply-To: <[email protected]> Cc: "Llewellyn, Grace (US 342C)" <[email protected]> --_000_MN2PR09MB60106941AE0F1CAAB3C53EEED3362MN2PR09MB6010namp_ Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Hi all, this is the error we have been seeing in our apache HTTP logs: [cache_disk:error] [pid 421298:tid 421362] (2)No such file or directory: [c= lient [REDACTED_IP]] AH00708: Cannot open data file /tmp/apache/[HASH_PATH]= /AA.data, referer: https://[REFERER_URL] When I check the cache, that file already exists and was created about the = same time the error message was triggered. I believe the problem could be a= race condition by .header being created before .data can be read from a sl= ightly earlier request, but I can=92t prove this based on the file creation= times which are rewritten after this error message is triggered and the ca= che is rewritten. I have been unable to recreate this problem even by trigg= ering a request with an extremely large .data file that takes longer than [= mod_cache: CacheLockMaxAge] to write I have ruled out the problem being that our cache is full and files can=92t= be written or htcacheclean being the problem by starting with a clean cach= e that begins to get these errors before it reaches its max size. I verifie= d that I am getting multiple consecutive requests when I see this error Some information about our configuration: * cache.conf has CacheLock on * This only happens on our production environment which gets millions o= f daily requests * I do not see any other relevant errors when I turn debug mode on * This is an infrequent error message, but it is reoccurring * We are using an overlay file system in a Docker container Has anyone encountered this issue before? I have not found an apache HTTP s= etting to lock reading the cache, only writing the cache Thank you, Grace --_000_MN2PR09MB60106941AE0F1CAAB3C53EEED3362MN2PR09MB6010namp_ Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable <html> <head> <meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3DWindows-1= 252"> </head> <body> <p style=3D"direction: ltr; text-align: left; text-indent: 0px; text-transf= orm: none;"> <span style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-size:= 12pt; color: rgb(0, 0, 0);">Hi all, this is the error we have been seeing = in our apache HTTP logs:</span></p> <pre><div class=3D"code-block--start" contenteditable=3D"false" dir=3D"ltr"= style=3D"color: inherit; background-color: inherit;"></div><div style=3D"b= ox-sizing: content-box; flex-shrink: 0; font-size: 0.875rem; padding: 8px; = width: 2rem; color: inherit; background-color: inherit;" contenteditable=3D= "false" dir=3D"ltr"><div class=3D"code-block-gutter-pseudo-element" data-la= bel=3D"1" style=3D"font-family: "Atlassian Mono", ui-monospace, M= enlo, "Segoe UI Mono", "Ubuntu Mono", monospace; text-a= lign: right; white-space: pre-wrap;"></div></div><div class=3D"code-content= " style=3D"text-align: left; text-indent: 0px; text-transform: none; font-s= ize: 12pt; color: rgb(0, 0, 0);"><code>[cache_disk:error] [pid 421298:tid 4= 21362] (2)No such file or directory: [client [REDACTED_IP]] AH00708: Cannot= open data file /tmp/apache/[HASH_PATH]/AA.data, referer: https://[REFERER_= URL]</code></div><div class=3D"code-block--end" contenteditable=3D"false" d= ir=3D"ltr" style=3D"color: inherit; background-color: inherit;"></div></pre= > <p style=3D"text-align: left; text-indent: 0px; text-transform: none;"><spa= n style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-size: 12p= t; color: rgb(0, 0, 0);">When I check the cache, that file already exists a= nd was created about the same time the error message was triggered. I believe the problem could be a race conditi= on by .header being created before .data can be read from a slightly earlie= r request, but I can=92t prove this based on the file creation times which = are rewritten after this error message is triggered and the cache is rewritten. I have been unable to recreate th= is problem even by triggering a request with an extremely large .data file = that takes longer than [mod_cache: CacheLockMaxAge] to write </span></= p> <p style=3D"text-align: left; text-indent: 0px; text-transform: none;"><spa= n style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-size: 12p= t; color: rgb(0, 0, 0);">I have ruled out the problem being that our cache = is full and files can=92t be written or htcacheclean being the problem by starting with a clean cache that begins = to get these errors before it reaches its max size. I verified that I am ge= tting multiple consecutive requests when I see this error</span></p> <p style=3D"text-align: left; text-indent: 0px; text-transform: none;"><spa= n style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-size: 12p= t; color: rgb(0, 0, 0);">Some information about our configuration: </s= pan></p> <ul data-prosemirror-content-type=3D"node" data-prosemirror-node-name=3D"bu= lletList" data-prosemirror-node-block=3D"true" style=3D"text-align: left;"> <li style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-size: 1= 2pt; color: rgb(0, 0, 0);"> <p role=3D"presentation"><span style=3D"text-transform: none;">cache.conf h= as CacheLock on</span></p> </li><li style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-si= ze: 12pt; color: rgb(0, 0, 0);"> <p role=3D"presentation"><span style=3D"text-transform: none;">This only ha= ppens on our production environment which gets millions of daily requests</= span></p> </li><li style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-si= ze: 12pt; color: rgb(0, 0, 0);"> <p role=3D"presentation"><span style=3D"text-transform: none;">I do not see= any other relevant errors when I turn debug mode on </span></p> </li><li style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-si= ze: 12pt; color: rgb(0, 0, 0);"> <p role=3D"presentation"><span style=3D"text-transform: none;">This is an i= nfrequent error message, but it is reoccurring </span></p> </li><li style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-si= ze: 12pt; color: rgb(0, 0, 0);"> <p role=3D"presentation"><span style=3D"text-transform: none;">We are using= an overlay file system in a Docker container </span></p> </li></ul> <p style=3D"text-align: left; text-indent: 0px; text-transform: none;"><spa= n style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-size: 12p= t; color: rgb(0, 0, 0);">Has anyone encountered this issue before? I have n= ot found an apache HTTP setting to lock reading the cache, only writing the cache </span></p> <p style=3D"text-align: left; text-indent: 0px; text-transform: none;"><spa= n style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-size: 12p= t; color: rgb(0, 0, 0);"><br> </span></p> <p style=3D"text-align: left; text-indent: 0px; text-transform: none;"><spa= n style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-size: 12p= t; color: rgb(0, 0, 0);">Thank you,</span></p> <p style=3D"text-align: left; text-indent: 0px; text-transform: none;"><spa= n style=3D"font-family: Aptos, Arial, Helvetica, sans-serif; font-size: 12p= t; color: rgb(0, 0, 0);">Grace </span></p> <div style=3D"direction: ltr; font-family: Aptos, Arial, Helvetica, sans-se= rif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div id=3D"ms-outlook-mobile-signature" style=3D"color: inherit; background= -color: inherit;"> <table class=3D"MsoNormalTable" id=3D"table_0" cellspacing=3D"0" cellpaddin= g=3D"0" style=3D"width: 467.25pt; box-sizing: border-box; border-collapse: = collapse; border-spacing: 0px;"> <tbody> <tr> <td class=3D"MsoNormalTable" style=3D"border-width: medium 1pt medium mediu= m; border-style: none solid none none; border-color: currentcolor windowtex= t currentcolor currentcolor; padding: 0in 5.4pt 0in 0.2in; width: 107.6pt; = height: 53px; box-sizing: border-box;"> <div class=3D"MsoNormalTable" style=3D"font-family: Aptos, Arial, Helvetica= , sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> </td> <td class=3D"MsoNormalTable" style=3D"padding: 0in 5.4pt 0in 0.2in; vertica= l-align: top; width: 359.9pt; height: 53px; box-sizing: border-box;"> </td> </tr> </tbody> </table> <div class=3D"MsoNormal" style=3D"margin: 0in; font-family: Calibri, sans-s= erif; font-size: 11pt;"> </div> </div> </body> </html> --_000_MN2PR09MB60106941AE0F1CAAB3C53EEED3362MN2PR09MB6010namp_--