DataStax Support Forums » User Favorites: blueplastic

DataStax Support Forums » User Favorites: blueplastic blueplastic Software, Support, and Training for Apache Cassandra en-US Thu, 23 May 2013 12:37:06 +0000 http://bbpress.org/?v=1.0.3 <![CDATA[Search]]> q http://www.datastax.com/support-forums/search.php thobbs on "Error loading cluster: No Cassandra connections available" http://www.datastax.com/support-forums/topic/error-loading-cluster-no-cassandra-connections-available#post-7487 Tue, 13 Nov 2012 17:14:19 +0000 thobbs 7487@http://www.datastax.com/support-forums/ Tamar, That log message indicates that opscenterd (the main daemon) cannot connect to your nodes over Thrift. First, make sure OpsCenter has an update set of node IP addresses by looking at the "Edit Cluster" page of OpsCenter. Second, make sure you don't have any firewalls preventing outside access to port 9160; you can test this by attempting to connect to nodes from the machine opscenterd is running on using cassandra-cli. (P.S. In the future, please start a new thread for new issues.) TamarFraenkel on "Error loading cluster: No Cassandra connections available" http://www.datastax.com/support-forums/topic/error-loading-cluster-no-cassandra-connections-available#post-7482 Tue, 13 Nov 2012 12:55:46 +0000 TamarFraenkel 7482@http://www.datastax.com/support-forums/ I am having the same issue after replacing a node in the cluser. In the log I see 2012-11-13 12:50:48+0000 [] Error fetching metric data: Traceback (most recent call last): Failure: opscenterd.CassandraService.NoCassandraConnection: No Cassandra connections available 2012-11-13 12:50:48+0000 [] Error fetching metric data: Traceback (most recent call last): Failure: opscenterd.CassandraService.NoCassandraConnection: No Cassandra connections available Anonymous on "Problem in DataStax documentation regarding keyspace creation" http://www.datastax.com/support-forums/topic/problem-in-datastax-documentation-regarding-keyspace-creation#post-555 Wed, 12 Oct 2011 15:38:07 +0000 Anonymous 555@http://www.datastax.com/support-forums/ I can confirm this. Both the problem as the solution provided are as described. daria on "OpsCenter install error" http://www.datastax.com/support-forums/topic/opscenter-install-error#post-514 Wed, 14 Sep 2011 22:05:29 +0000 daria 514@http://www.datastax.com/support-forums/ Thank you for letting us know! So the documentation now works for you as it is? blueplastic on "OpsCenter install error" http://www.datastax.com/support-forums/topic/opscenter-install-error#post-511 Wed, 14 Sep 2011 21:18:50 +0000 blueplastic 511@http://www.datastax.com/support-forums/ Just tried the command that wasn't working this morning, and it seems fine now. So, this worked: wget -O - <a href="http://debian.datastax.com/debian/repo_key" rel="nofollow">http://debian.datastax.com/debian/repo_key</a> | apt-key add - blueplastic on "OpsCenter install error" http://www.datastax.com/support-forums/topic/opscenter-install-error#post-510 Wed, 14 Sep 2011 19:07:33 +0000 blueplastic 510@http://www.datastax.com/support-forums/ When I run the command in step 5 of this page, I get an error: <a href="http://www.datastax.com/docs/opscenter/install_opscenter#opscenterd-install" rel="nofollow">http://www.datastax.com/docs/opscenter/install_opscenter#opscenterd-install</a> ubuntu@ip-10-90-x-x:~$ sudo wget -O - <a href="http://debian.datastax.com/debian/repo_key" rel="nofollow">http://debian.datastax.com/debian/repo_key</a> | apt-key add - --2011-09-14 19:01:39-- <a href="http://debian.datastax.com/debian/repo_key" rel="nofollow">http://debian.datastax.com/debian/repo_key</a> Resolving debian.datastax.com... 173.203.57.x Connecting to debian.datastax.com|173.203.57.x|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 2487 (2.4K) [application/octet-stream] Saving to: `STDOUT' 100%[===========================================================>] 2,487 --.-K/s in 0s 2011-09-14 19:01:39 (196 MB/s) - written to stdout [2487/2487] gpg: no writable keyring found: eof gpg: error reading `-': general error gpg: import from `-' failed: general error But if I change the URL to opscenter.datastax.com it works: ubuntu@ip-10-90-x-x:~$ wget -O - <a href="http://opscenter.datastax.com/debian/repo_key" rel="nofollow">http://opscenter.datastax.com/debian/repo_key</a> | sudo apt-key add - --2011-09-14 19:04:09-- <a href="http://opscenter.datastax.com/debian/repo_key" rel="nofollow">http://opscenter.datastax.com/debian/repo_key</a> Resolving opscenter.datastax.com... 173.203.x.x Connecting to opscenter.datastax.com|173.203.x.x|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 2487 (2.4K) [application/octet-stream] Saving to: `STDOUT' 100%[===========================================================>] 2,487 --.-K/s in 0s 2011-09-14 19:04:09 (195 MB/s) - written to stdout [2487/2487] OK nickmbailey on "Technical question about OpsCenter" http://www.datastax.com/support-forums/topic/technical-question-about-opscenter#post-404 Thu, 04 Aug 2011 19:35:11 +0000 nickmbailey 404@http://www.datastax.com/support-forums/ It would be possible to bundle the agent into the ami. The agent needs 3 things in order to work with opscenter: The ip for opscenter, the agent's own ip, and the correct ssl files. The ip for opscenter and the agent ip are located in a config file at '/var/lib/opscenter-agent/conf/address.yaml'. You will need to configure those properties correctly when the new ec2 server boots up. The ssl files that opscenter uses are generated when the main opscenter package is installed, and are lcoated in /var/lib/opscenter/ssl/. The correct files for the agent are then installed at /var/lib/opscenter-agent/ssl on the agent machines. You can use the same set of files between installations if you wish. So if you configure your machines to always use the same ssl files and configure the ips in address.yaml you should be able to do something like this. blueplastic on "Technical question about OpsCenter" http://www.datastax.com/support-forums/topic/technical-question-about-opscenter#post-403 Thu, 04 Aug 2011 18:55:24 +0000 blueplastic 403@http://www.datastax.com/support-forums/ I have a question about some of the details of OpsCenter's Column Family in Cassandra. We are working on building a recyclable demo of Cassandra in Amazon using custom AMIs and EBS volumes. I have a question about whether OpsCenter can be installed permanently into the AMIs or whether we would have to reinstall it each time we respawn the cluster (with different IPs) using the AMIs. Say I have 5 Amazon EC2 nodes running Brisk 1.0 and the first node has OpsCenter installed on it. The Cassandra database (including the OpsCenter CF) is not on the local ephemeral drives, but rather on EBS volumes that were connected to the 5 nodes. Then I permanently store each node as an AMI that I can relaunch later to respawn the cluster. So, typically we will terminate the 5 nodes, but keep the databases intact on the 5 EBS volumes. When we want to show a demo of Cassandra, we'll launch 5 new EC2 nodes (from 5 individualized AMIs) and reconnect the 5 EBS volumes to the new EC2 nodes. Note that the IP addresses for the new 5 nodes will be different than the old five nodes. We have some puppet scripts that will update the YAML file and other configuration files on the fresh 5 nodes before starting Cassandra. Casssandra restarts fine and reconnects to all of the databases on the EBS drive. But my question is regarding OpsCenter. When OpsCenter is first installed, it detects the Amazon Private IPs for all 5 nodes and installs Agents on them and creates a special OpsCenter Column Family to store metrics. My question is: In our recyclable demo, can we install OpsCenter on the first node and the agents on the rest of the nodes BEFORE saving our permanent AMIs? Are the private IPs for the cluster stored that OpsCenter Column family so that it would get confused/break if the cluster started up with different IPs? Currently, we don't have OpsCenter on the AMIs. Instead every time we launch a fresh 5 nodes, we reinstall OpsCenter and the Agents. We would like to automate this and make the respawn process faster by just baking OpsCenter into the AMI so even if we relaunch the cluster with new private IPs, we don't have to reinstall OpsCenter. Is it possible to do what we want to do? - Sameer blueplastic on "What is the correct procedure for dropping a hive table that is backed by a cassandra column family?" http://www.datastax.com/support-forums/topic/what-is-the-correct-procedure-for-dropping-a-hive-table-that-is-backed-by-a-cassandra-column-family#post-402 Wed, 03 Aug 2011 18:20:07 +0000 blueplastic 402@http://www.datastax.com/support-forums/ Also, I just noticed that before deleting a table in Hive, you may have to first delete the Column Family from Casandra-CLI. Then go back into Hive prompt and run: drop table KeySpaceName.ColumnFamilyName; joaquin on "Unbalanced ring on Cassandra side of Brisk cluster" http://www.datastax.com/support-forums/topic/unbalanced-ring-on-cassandra-side-of-brisk-cluster#post-393 Thu, 28 Jul 2011 20:55:10 +0000 joaquin 393@http://www.datastax.com/support-forums/ After investigating this further, this is a common side affect of not having your memory overcommitted for Brisk. Since Brisk has many components bundled under the same JVM, this is a requirement. Could you run: echo 1 | sudo tee /proc/sys/vm/overcommit_memory and let us know if this problem returns? After making this change, do your nodetool operations now complete successfully? Thanks, Joaquin joaquin on "Unbalanced ring on Cassandra side of Brisk cluster" http://www.datastax.com/support-forums/topic/unbalanced-ring-on-cassandra-side-of-brisk-cluster#post-391 Thu, 28 Jul 2011 20:36:33 +0000 joaquin 391@http://www.datastax.com/support-forums/ Could you add the line: JVM_OPTS="$JVM_OPTS -XX:ErrorFile=/path/to/file" at some point in cassandra-env.sh. You should find this under /etc/brisk/cassandra/cassandra-env.sh if you installed it via the packages or $BRISK_HOME/resources/cassandra/conf/cassandra-env.sh. This way we will be able to easily find your log. If this is not set, then typically the log will be in the folder that you called the process from. I'm having others look into this and will let you know what we find. Thanks, joaquin blueplastic on "Unbalanced ring on Cassandra side of Brisk cluster" http://www.datastax.com/support-forums/topic/unbalanced-ring-on-cassandra-side-of-brisk-cluster#post-386 Thu, 28 Jul 2011 19:00:38 +0000 blueplastic 386@http://www.datastax.com/support-forums/ You're right Joaquin. That EOFException error was not critical. It actually happened during the Cassandra start, not during the crash. Jonathan Ellis also said it was harmless on the Cassandra mailing list. However, we have tried running Repair and compaction on the node unbalanced node with no luck. Both Repair and Compaction seem to be crashing the Cassandra java process on the node. I eventually got repair to successfully complete on the node. Then yesterday, while running compaction, I got the following error in OpsCenter in the evening: 7/27/2011 11:30pm Alert Node reported as being down 10.2.206.x However, the system.log file for that node shows nothing but informational messages at that time: INFO [ScheduledTasks:1] 2011-07-28 06:29:21,429 GCInspector.java (line 128) GC for ParNew: 213 ms, 147241608 reclaimed leaving 2152005360 used; max is 4030726144 INFO [ScheduledTasks:1] 2011-07-28 06:29:28,622 GCInspector.java (line 128) GC for ParNew: 219 ms, 147301832 reclaimed leaving 2188187360 used; max is 4030726144 INFO [ScheduledTasks:1] 2011-07-28 06:29:39,666 GCInspector.java (line 128) GC for ParNew: 240 ms, 148102840 reclaimed leaving 2222749344 used; max is 4030726144 After that in the log, there is a long gap till I restart Cassandra this morning. Note that the time stamp in the log is different than what OpsCenter reports maybe because of EC2 or OpsCenter time zone stuff, but they are the same time. There was definitely something quirky with the Cassandra process on the node this morning. I couldn't run nodetool ring on it: Caused by: java.net.ConnectException: Connection refused at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351) I restarted the Cassandra process this morning and now OpsCenter has it marked as up, but I think Compaction is incomplete now. This shows me restarting the Cassandra process this morning: INFO [ScheduledTasks:1] 2011-07-28 06:29:21,429 GCInspector.java (line 128) GC for ParNew: 213 ms, 147241608 reclaimed leaving 2152005360 used; max is 4030726144 INFO [ScheduledTasks:1] 2011-07-28 06:29:28,622 GCInspector.java (line 128) GC for ParNew: 219 ms, 147301832 reclaimed leaving 2188187360 used; max is 4030726144 INFO [ScheduledTasks:1] 2011-07-28 06:29:39,666 GCInspector.java (line 128) GC for ParNew: 240 ms, 148102840 reclaimed leaving 2222749344 used; max is 4030726144 INFO [main] 2011-07-28 17:48:28,584 AbstractCassandraDaemon.java (line 78) Logging initialized INFO [main] 2011-07-28 17:48:28,617 AbstractCassandraDaemon.java (line 96) Heap size: 3894411264/3894411264 INFO [main] 2011-07-28 17:48:34,199 CLibrary.java (line 106) JNA mlockall successful I also checked the Linux syslog around that time (July 28 6:29am) and it looks like the OS dumped the java process? Jul 28 06:25:01 ip-10-2-206-127 CRON[15405]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1) Jul 28 06:25:01 ip-10-2-206-127 CRON[15406]: (root) CMD (test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )) Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627014] apt-get invoked oom-killer: gfp_mask=0x201da, order=0, oom_adj=0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627020] apt-get cpuset=/ mems_allowed=0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627025] Pid: 15420, comm: apt-get Not tainted 2.6.35-30-virtual #54-Ubuntu Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627027] Call Trace: Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627041] [<ffffffff810aefbd>] ? cpuset_print_task_mems_allowed+0x9d/0xb0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627048] [<ffffffff81104451>] dump_header+0x81/0xc0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627052] [<ffffffff81104511>] oom_kill_process+0x81/0x180 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627056] [<ffffffff81104a48>] __out_of_memory+0x58/0xd0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627059] [<ffffffff81104b46>] out_of_memory+0x86/0x1c0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627063] [<ffffffff811085ae>] __alloc_pages_slowpath+0x58e/0x5a0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627068] [<ffffffff8110872c>] __alloc_pages_nodemask+0x16c/0x1d0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627074] [<ffffffff8113aaaa>] alloc_pages_current+0x9a/0x100 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627078] [<ffffffff81101b57>] __page_cache_alloc+0x87/0x90 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627081] [<ffffffff8110168e>] ? find_get_page+0x1e/0x90 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627085] [<ffffffff81103113>] filemap_fault+0x1b3/0x450 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627091] [<ffffffff8111e3d4>] __do_fault+0x54/0x560 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627095] [<ffffffff81121379>] handle_mm_fault+0x1b9/0x440 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627101] [<ffffffff810072f2>] ? check_events+0x12/0x20 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627107] [<ffffffff815aaa35>] do_page_fault+0x125/0x350 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627111] [<ffffffff815a75b5>] page_fault+0x25/0x30 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627114] Mem-Info: Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627116] Node 0 DMA per-cpu: Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627119] CPU 0: hi: 0, btch: 1 usd: 0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627122] CPU 1: hi: 0, btch: 1 usd: 0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627124] Node 0 DMA32 per-cpu: Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627127] CPU 0: hi: 186, btch: 31 usd: 41 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627129] CPU 1: hi: 186, btch: 31 usd: 172 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627131] Node 0 Normal per-cpu: Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627134] CPU 0: hi: 186, btch: 31 usd: 0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627136] CPU 1: hi: 186, btch: 31 usd: 30 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627141] active_anon:665806 inactive_anon:133214 isolated_anon:0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627142] active_file:259 inactive_file:1039 isolated_file:0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627143] unevictable:1039172 dirty:0 writeback:259 unstable:0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627144] free:8797 slab_reclaimable:1978 slab_unreclaimable:3119 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627146] mapped:4552 shmem:49 pagetables:18095 bounce:0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627148] Node 0 DMA free:7808kB min:20kB low:24kB high:28kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15712kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627159] lowmem_reserve[]: 0 4024 7559 7559 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627165] Node 0 DMA32 free:22208kB min:5916kB low:7392kB high:8872kB active_anon:2135320kB inactive_anon:427136kB active_file:888kB inactive_file:3612kB unevictable:1425952kB isolated(anon):0kB isolated(file):0kB present:4120800kB mlocked:1425952kB dirty:0kB writeback:1036kB mapped:2532kB shmem:4kB slab_reclaimable:756kB slab_unreclaimable:4656kB kernel_stack:1240kB pagetables:50796kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:6976 all_unreclaimable? no Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627176] lowmem_reserve[]: 0 0 3535 3535 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627182] Node 0 Normal free:5172kB min:5196kB low:6492kB high:7792kB active_anon:527904kB inactive_anon:105720kB active_file:148kB inactive_file:544kB unevictable:2730736kB isolated(anon):0kB isolated(file):0kB present:3619840kB mlocked:2730736kB dirty:16kB writeback:0kB mapped:15676kB shmem:192kB slab_reclaimable:7156kB slab_unreclaimable:7820kB kernel_stack:2208kB pagetables:21584kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:1088 all_unreclaimable? yes Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627192] lowmem_reserve[]: 0 0 0 0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627197] Node 0 DMA: 2*4kB 1*8kB 1*16kB 1*32kB 1*64kB 2*128kB 1*256kB 0*512kB 1*1024kB 1*2048kB 1*4096kB = 7808kB Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627212] Node 0 DMA32: 672*4kB 662*8kB 501*16kB 4*32kB 1*64kB 1*128kB 1*256kB 1*512kB 1*1024kB 0*2048kB 1*4096kB = 22208kB Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627226] Node 0 Normal: 221*4kB 28*8kB 0*16kB 1*32kB 1*64kB 1*128kB 1*256kB 1*512kB 1*1024kB 1*2048kB 0*4096kB = 5172kB Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627257] 5640 total pagecache pages Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627260] 0 pages in swap cache Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627263] Swap cache stats: add 0, delete 0, find 0/0 Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627264] Free swap = 0kB Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.627266] Total swap = 0kB Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.652382] 1966064 pages RAM Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.652387] 54111 pages reserved Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.652388] 14176 pages shared Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.652390] 1897463 pages non-shared Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.652394] Out of memory: kill process 2126 (java) score 20305 or a child Jul 28 06:29:44 ip-10-2-206-127 kernel: [576488.652414] Killed process 2126 (java) vsz:951250956kB, anon-rss:4554448kB, file-rss:15276kB I don't see a JVM crashlog ( hs_err_pid[pid].log) in ~/brisk/resources/cassandra/bin or /tmp. So, I guess my question is: Why did the OS kill Java/Cassandra during compaction? Any more thoughts on why the ring would be so unbalanced? Also, I'm starting to suspect a bug in the random partitioner in 0.8.1? Has anyone loaded a large amount of data into 0.8.1? joaquin on "Unbalanced ring on Cassandra side of Brisk cluster" http://www.datastax.com/support-forums/topic/unbalanced-ring-on-cassandra-side-of-brisk-cluster#post-352 Tue, 26 Jul 2011 17:56:26 +0000 joaquin 352@http://www.datastax.com/support-forums/ That above error just means that a message either came in corrupt, got cut off, or another application pinged the Cassandra port. If you could use OpsCenter, MBeans, or nodetool netstats to watch the repair that would be great. Also if there are any other errors, that's something to look into, but this one is benign. Thanks, Joaquin joaquin on "Nodetool Repair status" http://www.datastax.com/support-forums/topic/nodetool-repair-status#post-350 Tue, 26 Jul 2011 17:47:29 +0000 joaquin 350@http://www.datastax.com/support-forums/ I remember looking for a string as well sometime back and just decided to confirm the repair was done using jconsole. You can also access the MBeans directly which is how OpsCenter reports back. Another option would be nodetool netstats to see what is currently in the queue for streaming. Thanks, Joaquin SVBridget on "What is the correct procedure for dropping a hive table that is backed by a cassandra column family?" http://www.datastax.com/support-forums/topic/what-is-the-correct-procedure-for-dropping-a-hive-table-that-is-backed-by-a-cassandra-column-family#post-345 Mon, 25 Jul 2011 21:44:52 +0000 SVBridget 345@http://www.datastax.com/support-forums/ So it seems that you can't drop or alter any table that you create by hand in a hive database that was auto-magically created from a cassandra keyspace. If you create your own hive database, then create hive tables that point to cassandra column families, then you can alter and drop those kinds of hive tables. IMO this is a bug - either you shouldn't be able to create any tables in auto-magically mapped hive databases, OR you should be able to alter and drop the tables you create by hand in an auto-magically mapped hive database.