Hello, PR27983 improvements attached Noah Noah On Thu, Jul 22, 2021 at 12:25 PM Noah Sanci wrote: > > Hello > > Please find the updated solution of PR27983 attached. > > Noah > > > Noah > > On Tue, Jul 20, 2021 at 10:42 AM Mark Wielaard wrote: > > > > Hi Noah, > > > > On Mon, Jul 19, 2021 at 09:31:17AM -0400, Noah Sanci wrote: > > > On Wed, Jul 14, 2021 at 12:36 PM Mark Wielaard wrote: > > > > You deduplicate the full URLs after they are fully constructed. Would > > > > it make sense to do the deduplication on server_url, maybe even as > > > > part of the Count number of URLs code? That might make the code > > > > simpler. And you can change num_urls upfront. > > > Deduplication before fully building the URL would work well, however I > > > was concerned about the slashbuildid situation. I would need to alter > > > all urls to either have a trailing '/' or no trailing '/' to ensure > > > comparison between 'http://127.0.0.1:8000/' and 'http://127.0.0.1:8000' > > > is considered equal. This is possible, but I ultimately decided to > > > wait until full construction as those issues would have been handled. > > > I would be glad to make the change if you want. > > > > I see what you mean, we have: > > > > /* Build handle url. Tolerate both http://foo:999 and > > http://foo:999/ forms */ > > char *slashbuildid; > > if (strlen(server_url) > 1 && server_url[strlen(server_url)-1] == '/') > > slashbuildid = "buildid"; > > else > > slashbuildid = "/buildid"; > > > > I think the code could become simpler if we did the deduplication of > > the server_url list up-front. That also gives you the oppertunity to > > make sure all server_urls end with a slash. But if you think that is > > too much work for this patch we can do it as a followup patch. You > > already included a test, which makes checking such a refactoring > > easier (sadly the run-debuginfod-find.sh test is somewhat fragile). > > > > > From be4e07a8732dd688595b99f92ba275ef5060a34d Mon Sep 17 00:00:00 2001 > > > From: Noah Sanci > > > Date: Fri, 9 Jul 2021 14:53:10 -0400 > > > Subject: [PATCH] debuginfod: PR27983 - ignore duplicate urls > > > > > > Gazing at server logs, one sees a minority of clients who appear to have > > > duplicate query traffic coming in: the same URL, milliseconds apart. > > > Chances are the user accidentally doubled her $DEBUGINFOD_URLS somehow, > > > and the client library is dutifully asking the servers TWICE. Bug #27863 > > > reduces the pain on the servers' CPU, but dupe network traffic is still > > > being paid. We should reject sending outright duplicate concurrent > > > traffic. > > > > > > https://sourceware.org/bugzilla/show_bug.cgi?id=27983 > > > > > > > diff --git a/debuginfod/debuginfod-client.c b/debuginfod/debuginfod-client.c > > > index f417b40a..a9447cae 100644 > > > --- a/debuginfod/debuginfod-client.c > > > +++ b/debuginfod/debuginfod-client.c > > > @@ -795,6 +795,7 @@ debuginfod_query_server (debuginfod_client *c, > > > > > > char *strtok_saveptr; > > > char *server_url = strtok_r(server_urls, url_delim, &strtok_saveptr); > > > + int unduplicated_urls = 0; > > > > > > /* Initialize each handle. */ > > > for (int i = 0; i < num_urls && server_url != NULL; i++) > > > > Maybe this should be: > > > > /* Initialize each handle. */ > > int i = 0; > > while (server_url != NULL) > > > > With an i++ at the end after the data[i] handle has been completely assigned. > > See below (*) for why. > > > > > + char *tmp_url = calloc(PATH_MAX, sizeof(char)); > > > > This can fail. So you'll have to handle tmp_url == NULL. Otherwise > > snprintf will crash. > > > > > if (filename) /* must start with / */ > > > - snprintf(data[i].url, PATH_MAX, "%s%s/%s/%s%s", server_url, > > > + snprintf(tmp_url, PATH_MAX, "%s%s/%s/%s%s", server_url, > > > slashbuildid, build_id_bytes, type, filename); > > > else > > > - snprintf(data[i].url, PATH_MAX, "%s%s/%s/%s", server_url, > > > + snprintf(tmp_url, PATH_MAX, "%s%s/%s/%s", server_url, > > > slashbuildid, build_id_bytes, type); > > > > > > + /* PR 27983: If the url is already set to be used use, skip it */ > > > + int url_index = -1; > > > + for (url_index = 0; url_index < i; ++url_index) > > > > No need to initialize url_index twice. Just declar int url_index; it > > will be assigned 0 at the next line. > > > > > + { > > > + if(strcmp(tmp_url, data[url_index].url) == 0) > > > + { > > > + url_index = -1; > > > + break; > > > + } > > > + } > > > + if (url_index == -1) > > > + { > > > + if (vfd >= 0) > > > + dprintf(vfd, "duplicate url: %s, skipping\n", tmp_url); > > > + free(tmp_url); > > > + // Ensure that next iteration doesn't skip over an index mid-array > > > + i--; > > > + server_url = strtok_r(NULL, url_delim, &strtok_saveptr); > > > + continue; > > > > (*) this i--; confused me a little. Which is why I suggest turning > > that for loop into a while loop. > > > > > + } > > > + else > > > + { > > > + unduplicated_urls++; > > > + strncpy(data[i].url, tmp_url, PATH_MAX); > > > > Both strings are max PATH_MAX chars, and tmp_url is zero terminated, > > so you can use strcpy. > > > > > + rc = -ENETUNREACH; > > > + goto out1; > > > + } > > > + data[i].client = c; > > > curl_easy_setopt(data[i].handle, CURLOPT_URL, data[i].url); > > > if (vfd >= 0) > > > curl_easy_setopt(data[i].handle, CURLOPT_ERRORBUFFER, data[i].errbuf); > > > @@ -863,6 +889,7 @@ debuginfod_query_server (debuginfod_client *c, > > > curl_multi_add_handle(curlm, data[i].handle); > > > server_url = strtok_r(NULL, url_delim, &strtok_saveptr); > > > > (*) So here a i++ (so you don't need the i-- above). > > > > > } > > > + num_urls = unduplicated_urls; > > > > > > /* Query servers in parallel. */ > > > if (vfd >= 0) > > > > Cheers, > > > > Mark > >