sqlplus 'adminuser@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=really.long.aws.string)(PORT=1521))(CONNECT_DATA=(SID=devdb)))'<\/p>\nERROR:
\nORA-21561: OID generation failed<\/code><\/p>\n
A new error message is still progress, right?<\/p>\n
I assumed the error meant the specified SID was incorrect. I had read in the AWS documentation somewhere that “the value for the Oracle SID will be the name of the DB instance’s database that you specified when you created the DB instance, not the name of the DB instance.” Since I had not created the DB instance, I was afraid I might never connect. However, that did not turn out to be the problem.<\/p>\n
Several sites suggested that the fix for “ORA-21561: OID generation failed” is to make sure that the hostname<\/code> and the \/etc\/hosts<\/code> entry for the machine match. Most of the posts online described people who were trying to connect to an Oracle DB on the the localhost machine. I figured that this suggestion was for the server-side and was therefore not relevant in my case. Besides, Oracle was running as a service and I had no access to the underlying server machine. However, it turns out that the hostname and hosts entry mismatch makes a difference for the client<\/em> machine as well.<\/p>\n# hostname
\nip-NNN-NNN-NNN-NNN<\/p>\n# head -1 \/etc\/hosts
\n127.0.0.1 localhost<\/code><\/p>\n
I updated the entry in \/etc\/hosts<\/code> to:
\n127.0.0.1 ip-NNN-NNN-NNN-NNN localhost<\/code><\/p>\nAnd then it worked!<\/p>\n
sqlplus 'adminuser@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=really.long.aws.string)(PORT=1521))(CONNECT_DATA=(SID=devdb)))'<\/p>\nEnter password:<\/p>\n
Connected to:
\nOracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
\nWith the Partitioning, Oracle Label Security, OLAP, Data Mining,
\nOracle Database Vault and Real Application Testing options<\/p>\n
SQL><\/code><\/p>\n
I realized that just because I could connect to it from my Linux machine would not help my colleagues who might want to access it from Windows. I installed the Oracle instant client (Basic + SQL*Plus) for Windows and tried connecting. It wouldn’t connect at all. I tried to test the connection:<\/p>\n
telnet really.long.aws.string 1521
\n'telnet' is not recognized as an internal or external command, operable program or batch file.<\/code><\/p>\nOh, Windows–why isn’t telnet installed by default? I enabled telnet via the Turn Windows features on or off<\/em> option in the Control Panel.<\/p>\ntelnet really.long.aws.string 1521
\nConnecting To really.long.aws.string...Could not open connection to the host, on port 1521: Connect failed<\/code><\/p>\nRight! I had added the IP address of the Linux machine, but I needed to add the IP address of the Windows machine to the AWS security group. After that, I could connect via telnet. I tried the connect string again:<\/p>\n
sqlplus 'adminuser@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=really.long.aws.string)(PORT=1521))(CONNECT_DATA=(SID=devdb)))'<\/p>\nERROR
\nORA-12560: TNS:protocol adapter error<\/code><\/p>\n
That error, as it turned out, indicated that sqlplus on Windows did not like the quoted connection string:<\/p>\n
C:\\oracle\\instant_client_12_1>sqlplus adminuser@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=really.long.aws.string)(PORT=1521))(CONNECT_DATA=(SID=devdb)))
\nSQL*Plus: Release 12.1.0.2.0 Production on Fri Oct 16 19:44:19 2015<\/p>\nCopyright (c) 1982, 2014, Oracle. All rights reserved.<\/p>\n
Enter password:<\/p>\n
Connected to:
\nOracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
\nWith the Partitioning, Oracle Label Security, OLAP, Data Mining,
\nOracle Database Vault and Real Application Testing options<\/p>\n
SQL><\/code><\/p>\n
It worked! Everything seemed quite straightforward once I’d made all the obvious mistakes.<\/p>\n","protected":false},"excerpt":{"rendered":"
A database isn’t very useful if you can’t connect to it. I describe my steps and mis-steps connecting to an Oracle database running as an AWS RDS instance using SQL*Plus on Linux and Windows.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[575,282],"tags":[363,278,274,364,368],"class_list":["post-1243","post","type-post","status-publish","format-standard","hentry","category-aws","category-oracle-2","tag-aws","tag-database","tag-oracle","tag-rds","tag-sqlplus"],"_links":{"self":[{"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/posts\/1243","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/comments?post=1243"}],"version-history":[{"count":15,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/posts\/1243\/revisions"}],"predecessor-version":[{"id":1351,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/posts\/1243\/revisions\/1351"}],"wp:attachment":[{"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/media?parent=1243"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/categories?post=1243"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/osric.com\/chris\/accidental-developer\/wp-json\/wp\/v2\/tags?post=1243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}