The same Docker image also works fine on some machine but fails consistently on other.<\/p>\n
The reason is this<\/a>. Docker is not good at \/dev\/random. Probably even more so if you run it in a VM, since it's double isolated from actual entropy sources (my non scientific observation). For whatever reason, OJDBC defaults to \/dev\/random and this causes a block when connecting to the database due to high probability of \/dev\/random depletion.<\/p>\n Simple solution is to just mount \/dev\/urandom to \/dev\/random inside the Docker, in docker run command: <\/p>\n Scenario: A JDK8 Docker container using OJDBC7 to connect to the database. Sounds simple enough, what could go wrong? Simptoms: Connecting to the database randomly takes several minutes, fails with a weird SqlRecoverableException: no more data to read from socket or just works fine as if there is no problem. The same Docker image also […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20,3],"tags":[],"class_list":["post-145","post","type-post","status-publish","format-standard","hentry","category-linux","category-programming"],"_links":{"self":[{"href":"https:\/\/xpam.pl\/blog\/index.php?rest_route=\/wp\/v2\/posts\/145","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xpam.pl\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/xpam.pl\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/xpam.pl\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/xpam.pl\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=145"}],"version-history":[{"count":3,"href":"https:\/\/xpam.pl\/blog\/index.php?rest_route=\/wp\/v2\/posts\/145\/revisions"}],"predecessor-version":[{"id":514,"href":"https:\/\/xpam.pl\/blog\/index.php?rest_route=\/wp\/v2\/posts\/145\/revisions\/514"}],"wp:attachment":[{"href":"https:\/\/xpam.pl\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=145"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xpam.pl\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=145"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xpam.pl\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=145"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n-v \/dev\/urandom:\/dev\/random<\/code>
\nSo.. if you ever want to use OJDBC inside Docker, remember this flag. It will save lives or at least spare you hours of useless debugging.<\/p>\n
\r\n
\r\n
Cen
\r\nGitHub<\/a>
\r\nEurobattle.net<\/a>
\r\nLagabuse.com<\/a>
\r\nBnetdocs<\/a>
\r\n<\/div>\r\n","protected":false},"excerpt":{"rendered":"