Re: Issue when deleting Cassandra rowKeys.
Hi, On Sun, Jan 27, 2013 at 12:05 AM, Michael Kjellman mkjell...@barracuda.comwrote: What is your gc_grace set to? Thanks for the info. I tried setting GcGraceSeconds for the column family to 0 since I have only one Cassandra node. still I can see the same behavior. ColumnFamily: bam_phone_retail_store_kpi Key Validation Class: org.apache.cassandra.db.marshal.BytesType Default column value validator: org.apache.cassandra.db.marshal.BytesType Columns sorted by: org.apache.cassandra.db.marshal.BytesType GC grace seconds: 0 Compaction min/max thresholds: 4/32 Read repair chance: 0.0 DC Local Read repair chance: 0.0 Replicate on write: false Caching: KEYS_ONLY Bloom Filter FP chance: default Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy Compression Options: chunk_length_kb: 128 sstable_compression: org.apache.cassandra.io.compress.SnappyCompressor I am using Cassandra 1.1.3. Appreciate your help on solving this. Thanks, Kasun. Are your findings before or after this time after the deletion? From: Kasun Weranga kas...@wso2.com Reply-To: user@cassandra.apache.org user@cassandra.apache.org Date: Saturday, January 26, 2013 10:33 AM To: user@cassandra.apache.org user@cassandra.apache.org, d...@cassandra.apache.org d...@cassandra.apache.org Subject: Issue when deleting Cassandra rowKeys. Hi all, When I delete some rowkeys programmatically I can see two rowkeys remains in the column family. I think it is due to tombstones. Is there a way to remove it when deleting rowkeys. Can I run compaction programmatically after deletion? will it remove all these remaining rowkeys. Thanks, Kasun.
Re: Issue when deleting Cassandra rowKeys.
Hi, After running compaction tombstones get removed. So It seems like only setting GC grace seconds to lower value is not enough. Am I correct ? Thanks, Kasun On Sun, Jan 27, 2013 at 1:31 PM, Kasun Weranga kas...@wso2.com wrote: Hi, On Sun, Jan 27, 2013 at 12:05 AM, Michael Kjellman mkjell...@barracuda.com wrote: What is your gc_grace set to? Thanks for the info. I tried setting GcGraceSeconds for the column family to 0 since I have only one Cassandra node. still I can see the same behavior. ColumnFamily: bam_phone_retail_store_kpi Key Validation Class: org.apache.cassandra.db.marshal.BytesType Default column value validator: org.apache.cassandra.db.marshal.BytesType Columns sorted by: org.apache.cassandra.db.marshal.BytesType GC grace seconds: 0 Compaction min/max thresholds: 4/32 Read repair chance: 0.0 DC Local Read repair chance: 0.0 Replicate on write: false Caching: KEYS_ONLY Bloom Filter FP chance: default Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy Compression Options: chunk_length_kb: 128 sstable_compression: org.apache.cassandra.io.compress.SnappyCompressor I am using Cassandra 1.1.3. Appreciate your help on solving this. Thanks, Kasun. Are your findings before or after this time after the deletion? From: Kasun Weranga kas...@wso2.com Reply-To: user@cassandra.apache.org user@cassandra.apache.org Date: Saturday, January 26, 2013 10:33 AM To: user@cassandra.apache.org user@cassandra.apache.org, d...@cassandra.apache.org d...@cassandra.apache.org Subject: Issue when deleting Cassandra rowKeys. Hi all, When I delete some rowkeys programmatically I can see two rowkeys remains in the column family. I think it is due to tombstones. Is there a way to remove it when deleting rowkeys. Can I run compaction programmatically after deletion? will it remove all these remaining rowkeys. Thanks, Kasun.
Denormalization
Hi. Since denormalized data is first-class citizen in Cassandra, how to handle updating denormalized data. E.g. If we have a USER cf with name, email etc. and denormalize user data into many other CF:s and then update the information about a user (name, email...). What is the best way to handle updating those user data properties which might be spread out over many cf:s and many rows? Regards /Fredrik
Re: Denormalization
There is a really a mix of denormalization and normalization. It really depends on specific use-cases. To get better help on the email list, a more specific use case may be appropriate. Dean On 1/27/13 2:03 PM, Fredrik Stigbäck fredrik.l.stigb...@sitevision.se wrote: Hi. Since denormalized data is first-class citizen in Cassandra, how to handle updating denormalized data. E.g. If we have a USER cf with name, email etc. and denormalize user data into many other CF:s and then update the information about a user (name, email...). What is the best way to handle updating those user data properties which might be spread out over many cf:s and many rows? Regards /Fredrik
Re: Denormalization
I don't have a current use-case. I was just curious how applications handle and how to think when modelling, since I guess denormalization might increase the complexity of the application. Fredrik 2013/1/27 Hiller, Dean dean.hil...@nrel.gov: There is a really a mix of denormalization and normalization. It really depends on specific use-cases. To get better help on the email list, a more specific use case may be appropriate. Dean On 1/27/13 2:03 PM, Fredrik Stigbäck fredrik.l.stigb...@sitevision.se wrote: Hi. Since denormalized data is first-class citizen in Cassandra, how to handle updating denormalized data. E.g. If we have a USER cf with name, email etc. and denormalize user data into many other CF:s and then update the information about a user (name, email...). What is the best way to handle updating those user data properties which might be spread out over many cf:s and many rows? Regards /Fredrik -- Fredrik Larsson Stigbäck SiteVision AB Vasagatan 10, 107 10 Örebro 019-17 30 30
Re: Denormalization
In my experience, if you foresee needing to do a lot of updates where a master record would need to propagate its changes to other records, then in general a non-sql based data store may be the wrong fit for your data. If you have a lot of data that doesn't really change or is not linked in some way to other rows (in Cassandra's case). Then a non-sql based data store could be a great fit. Yes, you can do some fancy stuff to force things like Cassandra to behave like an RDBMS, but it's at the cost of application complexity; more code, more bugs. I often end up mixing the data stores sql/non-sql to play to their respective strengths. If I start seeing a lot of related data, relational databases are really good at solving that problem. On Sunday, January 27, 2013, Fredrik Stigbäck wrote: I don't have a current use-case. I was just curious how applications handle and how to think when modelling, since I guess denormalization might increase the complexity of the application. Fredrik 2013/1/27 Hiller, Dean dean.hil...@nrel.gov javascript:;: There is a really a mix of denormalization and normalization. It really depends on specific use-cases. To get better help on the email list, a more specific use case may be appropriate. Dean On 1/27/13 2:03 PM, Fredrik Stigbäck fredrik.l.stigb...@sitevision.sejavascript:; wrote: Hi. Since denormalized data is first-class citizen in Cassandra, how to handle updating denormalized data. E.g. If we have a USER cf with name, email etc. and denormalize user data into many other CF:s and then update the information about a user (name, email...). What is the best way to handle updating those user data properties which might be spread out over many cf:s and many rows? Regards /Fredrik -- Fredrik Larsson Stigbäck SiteVision AB Vasagatan 10, 107 10 Örebro 019-17 30 30
Re: Denormalization
Things like PlayOrm exist to help you with half and half of denormalized and normalized data. There are more and more patterns out there of denormalization and normalization but allowing for scalability still. Here is one patterns page https://github.com/deanhiller/playorm/wiki/Patterns-Page Dean From: Adam Venturella aventure...@gmail.commailto:aventure...@gmail.com Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.org user@cassandra.apache.orgmailto:user@cassandra.apache.org Date: Sunday, January 27, 2013 3:44 PM To: user@cassandra.apache.orgmailto:user@cassandra.apache.org user@cassandra.apache.orgmailto:user@cassandra.apache.org Subject: Re: Denormalization In my experience, if you foresee needing to do a lot of updates where a master record would need to propagate its changes to other records, then in general a non-sql based data store may be the wrong fit for your data. If you have a lot of data that doesn't really change or is not linked in some way to other rows (in Cassandra's case). Then a non-sql based data store could be a great fit. Yes, you can do some fancy stuff to force things like Cassandra to behave like an RDBMS, but it's at the cost of application complexity; more code, more bugs. I often end up mixing the data stores sql/non-sql to play to their respective strengths. If I start seeing a lot of related data, relational databases are really good at solving that problem. On Sunday, January 27, 2013, Fredrik Stigbäck wrote: I don't have a current use-case. I was just curious how applications handle and how to think when modelling, since I guess denormalization might increase the complexity of the application. Fredrik 2013/1/27 Hiller, Dean dean.hil...@nrel.govjavascript:;: There is a really a mix of denormalization and normalization. It really depends on specific use-cases. To get better help on the email list, a more specific use case may be appropriate. Dean On 1/27/13 2:03 PM, Fredrik Stigbäck fredrik.l.stigb...@sitevision.sejavascript:; wrote: Hi. Since denormalized data is first-class citizen in Cassandra, how to handle updating denormalized data. E.g. If we have a USER cf with name, email etc. and denormalize user data into many other CF:s and then update the information about a user (name, email...). What is the best way to handle updating those user data properties which might be spread out over many cf:s and many rows? Regards /Fredrik -- Fredrik Larsson Stigbäck SiteVision AB Vasagatan 10, 107 10 Örebro 019-17 30 30
Re: Denormalization
Oh and check out the last pattern Scalable equals only index which can allow you to still have normalized data though the pattern does denormalization just enough that you can 1. Update just two pieces of info (the users email for instance and the Xref table email as well). 2. Allow everyone else to have foreign references into that piece. (everyone references the guid not the email….while the xref table has an email to guid for your use…this can be quite a common pattern actually when you may be having issues denormalizing) Dean From: Adam Venturella aventure...@gmail.commailto:aventure...@gmail.com Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.org user@cassandra.apache.orgmailto:user@cassandra.apache.org Date: Sunday, January 27, 2013 3:44 PM To: user@cassandra.apache.orgmailto:user@cassandra.apache.org user@cassandra.apache.orgmailto:user@cassandra.apache.org Subject: Re: Denormalization In my experience, if you foresee needing to do a lot of updates where a master record would need to propagate its changes to other records, then in general a non-sql based data store may be the wrong fit for your data. If you have a lot of data that doesn't really change or is not linked in some way to other rows (in Cassandra's case). Then a non-sql based data store could be a great fit. Yes, you can do some fancy stuff to force things like Cassandra to behave like an RDBMS, but it's at the cost of application complexity; more code, more bugs. I often end up mixing the data stores sql/non-sql to play to their respective strengths. If I start seeing a lot of related data, relational databases are really good at solving that problem. On Sunday, January 27, 2013, Fredrik Stigbäck wrote: I don't have a current use-case. I was just curious how applications handle and how to think when modelling, since I guess denormalization might increase the complexity of the application. Fredrik 2013/1/27 Hiller, Dean dean.hil...@nrel.govjavascript:;: There is a really a mix of denormalization and normalization. It really depends on specific use-cases. To get better help on the email list, a more specific use case may be appropriate. Dean On 1/27/13 2:03 PM, Fredrik Stigbäck fredrik.l.stigb...@sitevision.sejavascript:; wrote: Hi. Since denormalized data is first-class citizen in Cassandra, how to handle updating denormalized data. E.g. If we have a USER cf with name, email etc. and denormalize user data into many other CF:s and then update the information about a user (name, email...). What is the best way to handle updating those user data properties which might be spread out over many cf:s and many rows? Regards /Fredrik -- Fredrik Larsson Stigbäck SiteVision AB Vasagatan 10, 107 10 Örebro 019-17 30 30
Re: Cassandra Consistency problem with NTP
Just FYI, For one of the projects, i got around the NTP Drift problem by always reading more than i need, For example i want to read all the messages before x seconds then i would query cassandra for (x seconds + 500ms) then filter the duplicates in the client. Yes it does more network and yes client needs more logic to handle it. Regards, /VJ On Thu, Jan 17, 2013 at 10:47 AM, Edward Capriolo edlinuxg...@gmail.comwrote: If you have 40ms NTP drift something is VERY VERY wrong. You should have a local NTP server on the same subnet, do not try to use one on the moon. On Thu, Jan 17, 2013 at 4:42 AM, Sylvain Lebresne sylv...@datastax.comwrote: So what I want is, Cassandra provide some information for client, to indicate A is stored before B, e.g. global unique timestamp, or row order. The row order is determined by 1) the comparator you use for the column family and 2) the column names you, the client, choose for A and B. So what are the column names you use for A and B? Now what you could do is use a TimeUUID comparator for that column family and use a time uuid for A and B column names. In that case, provided A and B are sent from the same client node and B is sent after A on that client (which you said is the case), then any non buggy time uuid generator will guarantee that the uuid generated for A will be smaller than the one for B and thus that in Cassandra, A will be sorted before B. In any case, the point I want to make is that Cassandra itself cannot do anything for you problem, because by design the row ordering is something entirely controlled client side (and just so there is no misunderstanding, I want to make that point not because I'm not trying to suggest you were wrong asking this mailing list, but because we can't suggest a proper solution unless we clearly understand what the problem is). -- Sylvain 2013/1/17 Sylvain Lebresne sylv...@datastax.com I'm not sure I fully understand your problem. You seem to be talking of ordering the requests, in the order they are generated. But in that case, you will rely on the ordering of columns within whatever row you store request A and B in, and that order depends on the column names, which in turns is client provided and doesn't depend at all of the time synchronization of the cluster nodes. And since you are able to say that request A comes before B, I suppose this means said requests are generated from the same source. In which case you just need to make sure that the column names storing each request respect the correct ordering. The column timestamps Cassandra uses are here to which update *to the same column* is the more recent one. So it only comes into play if you requests A and B update the same column and you're interested in knowing which one of the update will win when you read. But even if that's your case (which doesn't sound like it at all from your description), the column timestamp is only generated server side if you use CQL. And even in that latter case, it's a convenience and you can force a timestamp client side if you really wish. In other words, Cassandra dependency on time synchronization is not a strong one even in that case. But again, that doesn't seem at all to be the problem you are trying to solve. -- Sylvain On Thu, Jan 17, 2013 at 2:56 AM, Jason Tang ares.t...@gmail.comwrote: Hi I am using Cassandra in a message bus solution, the major responsibility of cassandra is recording the incoming requests for later consumming. One strategy is First in First out (FIFO), so I need to get the stored request in reversed order. I use NTP to synchronize the system time for the nodes in the cluster. (4 nodes). But the local time of each node are still have some inaccuracy, around 40 ms. The consistency level is write all and read one, and replicate factor is 3. But here is the problem: A request come to node One at local time PM 10:00:01.000 B request come to node Two at local time PM 10:00:00.980 The correct order is A -- B But the timestamp is B -- A So is there any way for Cassandra to keep the correct order for read operation? (e.g. logical timestamp ?) Or Cassandra strong depence on time synchronization solution? BRs //Tang
Re: Denormalization
One technique is on the client side you build a tool that takes the even and produces N mutations. In c* writes are cheap so essentially, re-write everything on all changes. On Sun, Jan 27, 2013 at 4:03 PM, Fredrik Stigbäck fredrik.l.stigb...@sitevision.se wrote: Hi. Since denormalized data is first-class citizen in Cassandra, how to handle updating denormalized data. E.g. If we have a USER cf with name, email etc. and denormalize user data into many other CF:s and then update the information about a user (name, email...). What is the best way to handle updating those user data properties which might be spread out over many cf:s and many rows? Regards /Fredrik
Re: Denormalization
When I said that writes were cheap, I was speaking that in a normal case people are making 2-10 inserts what in a relational database might be one. 30K inserts is certainly not cheap. Your use case with 30,000 inserts is probably a special case. Most directory services that I am aware of OpenLDAP, Active Directory, Sun Directory server do eventually consistent master/slave and multi-master replication. So no worries about having to background something. You just want the replication to be fast enough so that when you call the employee about to be fired into the office, that by the time he leaves and gets home he can not VPN to rm -rf / your main file server :) On Sun, Jan 27, 2013 at 7:57 PM, Hiller, Dean dean.hil...@nrel.gov wrote: Sometimes this is true, sometimes not…..….We have a use case where we have an admin tool where we choose to do this denorm for ACL on permission checks to make permission checks extremely fast. That said, we have one issue with one object that too many children(30,000) so when someone gives a user access to this one object with 30,000 children, we end up with a bad 60 second wait and users ended up getting frustrated and trying to cancel(our plan since admin activity hardly ever happens is to do it on our background thread and just return immediately to the user and tell him his changes will take affect in 1 minute ). After all, admin changes are infrequent anyways. This example demonstrates how sometimes it could almost burn you. I guess my real point is it really depends on your use cases ;). In a lot of cases denorm can work but in some cases it burns you so you have to balance it all. In 90% of our cases our denorm is working great and for this one case, we need to background the permission change as we still LOVE the performance of our ACL checks. Ps. 30,000 writes in cassandra is not cheap when done from one server ;) but in general parallized writes is very fast for like 500. Later, Dean From: Edward Capriolo edlinuxg...@gmail.commailto:edlinuxg...@gmail.com Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.org user@cassandra.apache.orgmailto:user@cassandra.apache.org Date: Sunday, January 27, 2013 5:50 PM To: user@cassandra.apache.orgmailto:user@cassandra.apache.org user@cassandra.apache.orgmailto:user@cassandra.apache.org Subject: Re: Denormalization One technique is on the client side you build a tool that takes the even and produces N mutations. In c* writes are cheap so essentially, re-write everything on all changes. On Sun, Jan 27, 2013 at 4:03 PM, Fredrik Stigbäck fredrik.l.stigb...@sitevision.semailto:fredrik.l.stigb...@sitevision.se wrote: Hi. Since denormalized data is first-class citizen in Cassandra, how to handle updating denormalized data. E.g. If we have a USER cf with name, email etc. and denormalize user data into many other CF:s and then update the information about a user (name, email...). What is the best way to handle updating those user data properties which might be spread out over many cf:s and many rows? Regards /Fredrik
Re: Denormalization
Agreed, was just making sure others knew ;). Dean From: Edward Capriolo edlinuxg...@gmail.commailto:edlinuxg...@gmail.com Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.org user@cassandra.apache.orgmailto:user@cassandra.apache.org Date: Sunday, January 27, 2013 6:51 PM To: user@cassandra.apache.orgmailto:user@cassandra.apache.org user@cassandra.apache.orgmailto:user@cassandra.apache.org Subject: Re: Denormalization When I said that writes were cheap, I was speaking that in a normal case people are making 2-10 inserts what in a relational database might be one. 30K inserts is certainly not cheap. Your use case with 30,000 inserts is probably a special case. Most directory services that I am aware of OpenLDAP, Active Directory, Sun Directory server do eventually consistent master/slave and multi-master replication. So no worries about having to background something. You just want the replication to be fast enough so that when you call the employee about to be fired into the office, that by the time he leaves and gets home he can not VPN to rm -rf / your main file server :) On Sun, Jan 27, 2013 at 7:57 PM, Hiller, Dean dean.hil...@nrel.govmailto:dean.hil...@nrel.gov wrote: Sometimes this is true, sometimes not…..….We have a use case where we have an admin tool where we choose to do this denorm for ACL on permission checks to make permission checks extremely fast. That said, we have one issue with one object that too many children(30,000) so when someone gives a user access to this one object with 30,000 children, we end up with a bad 60 second wait and users ended up getting frustrated and trying to cancel(our plan since admin activity hardly ever happens is to do it on our background thread and just return immediately to the user and tell him his changes will take affect in 1 minute ). After all, admin changes are infrequent anyways. This example demonstrates how sometimes it could almost burn you. I guess my real point is it really depends on your use cases ;). In a lot of cases denorm can work but in some cases it burns you so you have to balance it all. In 90% of our cases our denorm is working great and for this one case, we need to background the permission change as we still LOVE the performance of our ACL checks. Ps. 30,000 writes in cassandra is not cheap when done from one server ;) but in general parallized writes is very fast for like 500. Later, Dean From: Edward Capriolo edlinuxg...@gmail.commailto:edlinuxg...@gmail.commailto:edlinuxg...@gmail.commailto:edlinuxg...@gmail.com Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.orgmailto:user@cassandra.apache.orgmailto:user@cassandra.apache.org user@cassandra.apache.orgmailto:user@cassandra.apache.orgmailto:user@cassandra.apache.orgmailto:user@cassandra.apache.org Date: Sunday, January 27, 2013 5:50 PM To: user@cassandra.apache.orgmailto:user@cassandra.apache.orgmailto:user@cassandra.apache.orgmailto:user@cassandra.apache.org user@cassandra.apache.orgmailto:user@cassandra.apache.orgmailto:user@cassandra.apache.orgmailto:user@cassandra.apache.org Subject: Re: Denormalization One technique is on the client side you build a tool that takes the even and produces N mutations. In c* writes are cheap so essentially, re-write everything on all changes. On Sun, Jan 27, 2013 at 4:03 PM, Fredrik Stigbäck fredrik.l.stigb...@sitevision.semailto:fredrik.l.stigb...@sitevision.semailto:fredrik.l.stigb...@sitevision.semailto:fredrik.l.stigb...@sitevision.se wrote: Hi. Since denormalized data is first-class citizen in Cassandra, how to handle updating denormalized data. E.g. If we have a USER cf with name, email etc. and denormalize user data into many other CF:s and then update the information about a user (name, email...). What is the best way to handle updating those user data properties which might be spread out over many cf:s and many rows? Regards /Fredrik
Re: Issue when deleting Cassandra rowKeys.
Deletes must be written to disk otherwise they are lost. Cheers - Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 28/01/2013, at 3:29 AM, Kasun Weranga kas...@wso2.com wrote: Hi, After running compaction tombstones get removed. So It seems like only setting GC grace seconds to lower value is not enough. Am I correct ? Thanks, Kasun On Sun, Jan 27, 2013 at 1:31 PM, Kasun Weranga kas...@wso2.com wrote: Hi, On Sun, Jan 27, 2013 at 12:05 AM, Michael Kjellman mkjell...@barracuda.com wrote: What is your gc_grace set to? Thanks for the info. I tried setting GcGraceSeconds for the column family to 0 since I have only one Cassandra node. still I can see the same behavior. ColumnFamily: bam_phone_retail_store_kpi Key Validation Class: org.apache.cassandra.db.marshal.BytesType Default column value validator: org.apache.cassandra.db.marshal.BytesType Columns sorted by: org.apache.cassandra.db.marshal.BytesType GC grace seconds: 0 Compaction min/max thresholds: 4/32 Read repair chance: 0.0 DC Local Read repair chance: 0.0 Replicate on write: false Caching: KEYS_ONLY Bloom Filter FP chance: default Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy Compression Options: chunk_length_kb: 128 sstable_compression: org.apache.cassandra.io.compress.SnappyCompressor I am using Cassandra 1.1.3. Appreciate your help on solving this. Thanks, Kasun. Are your findings before or after this time after the deletion? From: Kasun Weranga kas...@wso2.com Reply-To: user@cassandra.apache.org user@cassandra.apache.org Date: Saturday, January 26, 2013 10:33 AM To: user@cassandra.apache.org user@cassandra.apache.org, d...@cassandra.apache.org d...@cassandra.apache.org Subject: Issue when deleting Cassandra rowKeys. Hi all, When I delete some rowkeys programmatically I can see two rowkeys remains in the column family. I think it is due to tombstones. Is there a way to remove it when deleting rowkeys. Can I run compaction programmatically after deletion? will it remove all these remaining rowkeys. Thanks, Kasun.
Flume-cassandra
hi, I am storing flume events in to cassandra by using simpleCassandraSink. when i am storing a single event to cassandra from flume collector source in Cassandra i am getting nearly 100 rows , in which 1 row is containg my data and other rows are blank. So how do i solve this problem . Please provide me some help. Thank you
Re: Flume-cassandra
FYI, Not sure about this particular problem, https://github.com/Vijay2win/flume-cassandra-sink supports latest flume version, if you want to try it out. Regards, /VJ On Sun, Jan 27, 2013 at 8:05 PM, Sri Ramya ramya.1...@gmail.com wrote: hi, I am storing flume events in to cassandra by using simpleCassandraSink. when i am storing a single event to cassandra from flume collector source in Cassandra i am getting nearly 100 rows , in which 1 row is containg my data and other rows are blank. So how do i solve this problem . Please provide me some help. Thank you
Accessing Metadata of Column Familes
Hello, I wish to access metadata information on column families. How can I do it? Any ideas? Thanks and Regards Rishabh Agrawal NOTE: This message may contain information that is confidential, proprietary, privileged or otherwise protected by law. The message is intended solely for the named addressee. If received in error, please destroy and notify the sender. Any use of this email is prohibited when received in error. Impetus does not represent, warrant and/or guarantee, that the integrity of this communication has been maintained nor that the communication is free of errors, virus, interception or interference.
RE: Accessing Metadata of Column Familes
Which API are you using? If you are using Hector use ColumnFamilyDefinition. Regards Harshvardhan OJha From: Rishabh Agrawal [mailto:rishabh.agra...@impetus.co.in] Sent: Monday, January 28, 2013 12:16 PM To: user@cassandra.apache.org Subject: Accessing Metadata of Column Familes Hello, I wish to access metadata information on column families. How can I do it? Any ideas? Thanks and Regards Rishabh Agrawal NOTE: This message may contain information that is confidential, proprietary, privileged or otherwise protected by law. The message is intended solely for the named addressee. If received in error, please destroy and notify the sender. Any use of this email is prohibited when received in error. Impetus does not represent, warrant and/or guarantee, that the integrity of this communication has been maintained nor that the communication is free of errors, virus, interception or interference. The contents of this email, including the attachments, are PRIVILEGED AND CONFIDENTIAL to the intended recipient at the email address to which it has been addressed. If you receive it in error, please notify the sender immediately by return email and then permanently delete it from your system. The unauthorized use, distribution, copying or alteration of this email, including the attachments, is strictly forbidden. Please note that neither MakeMyTrip nor the sender accepts any responsibility for viruses and it is your responsibility to scan the email and attachments (if any). No contracts may be concluded on behalf of MakeMyTrip by means of email communications.
RE: Accessing Metadata of Column Familes
Thank for the reply. I do not want to go by API route. I wish to access files and column families which store meta data information From: Harshvardhan Ojha [mailto:harshvardhan.o...@makemytrip.com] Sent: Monday, January 28, 2013 12:25 PM To: user@cassandra.apache.org Subject: RE: Accessing Metadata of Column Familes Which API are you using? If you are using Hector use ColumnFamilyDefinition. Regards Harshvardhan OJha From: Rishabh Agrawal [mailto:rishabh.agra...@impetus.co.in] Sent: Monday, January 28, 2013 12:16 PM To: user@cassandra.apache.org Subject: Accessing Metadata of Column Familes Hello, I wish to access metadata information on column families. How can I do it? Any ideas? Thanks and Regards Rishabh Agrawal NOTE: This message may contain information that is confidential, proprietary, privileged or otherwise protected by law. The message is intended solely for the named addressee. If received in error, please destroy and notify the sender. Any use of this email is prohibited when received in error. Impetus does not represent, warrant and/or guarantee, that the integrity of this communication has been maintained nor that the communication is free of errors, virus, interception or interference. The contents of this email, including the attachments, are PRIVILEGED AND CONFIDENTIAL to the intended recipient at the email address to which it has been addressed. If you receive it in error, please notify the sender immediately by return email and then permanently delete it from your system. The unauthorized use, distribution, copying or alteration of this email, including the attachments, is strictly forbidden. Please note that neither MakeMyTrip nor the sender accepts any responsibility for viruses and it is your responsibility to scan the email and attachments (if any). No contracts may be concluded on behalf of MakeMyTrip by means of email communications. NOTE: This message may contain information that is confidential, proprietary, privileged or otherwise protected by law. The message is intended solely for the named addressee. If received in error, please destroy and notify the sender. Any use of this email is prohibited when received in error. Impetus does not represent, warrant and/or guarantee, that the integrity of this communication has been maintained nor that the communication is free of errors, virus, interception or interference.
Re: Accessing Metadata of Column Familes
Just use DESCRIBE command in cqlsh. Refer to this link http://www.datastax.com/docs/1.1/references/cql/DESCRIBE On Mon, Jan 28, 2013 at 12:24 PM, Harshvardhan Ojha harshvardhan.o...@makemytrip.com wrote: Which API are you using? If you are using Hector use ColumnFamilyDefinition. Regards Harshvardhan OJha *From:* Rishabh Agrawal [mailto:rishabh.agra...@impetus.co.in] *Sent:* Monday, January 28, 2013 12:16 PM *To:* user@cassandra.apache.org *Subject:* Accessing Metadata of Column Familes Hello, I wish to access metadata information on column families. How can I do it? Any ideas? Thanks and Regards Rishabh Agrawal -- NOTE: This message may contain information that is confidential, proprietary, privileged or otherwise protected by law. The message is intended solely for the named addressee. If received in error, please destroy and notify the sender. Any use of this email is prohibited when received in error. Impetus does not represent, warrant and/or guarantee, that the integrity of this communication has been maintained nor that the communication is free of errors, virus, interception or interference. The contents of this email, including the attachments, are *PRIVILEGED AND CONFIDENTIAL* to the intended recipient at the email address to which it has been addressed. If you receive it in error, please notify the sender immediately by return email and then permanently delete it from your system. The unauthorized use, distribution, copying or alteration of this email, including the attachments, is strictly forbidden. Please note that neither MakeMyTrip nor the sender accepts any responsibility for viruses and it is your responsibility to scan the email and attachments (if any). No contracts may be concluded on behalf of *MakeMyTrip* by means of email communications. -- Abhijit Chanda +91-974395
RE: Accessing Metadata of Column Familes
You can get storage attributes from /data/system/ keyspace. From: Rishabh Agrawal [mailto:rishabh.agra...@impetus.co.in] Sent: Monday, January 28, 2013 12:42 PM To: user@cassandra.apache.org Subject: RE: Accessing Metadata of Column Familes Thank for the reply. I do not want to go by API route. I wish to access files and column families which store meta data information From: Harshvardhan Ojha [mailto:harshvardhan.o...@makemytrip.com] Sent: Monday, January 28, 2013 12:25 PM To: user@cassandra.apache.org Subject: RE: Accessing Metadata of Column Familes Which API are you using? If you are using Hector use ColumnFamilyDefinition. Regards Harshvardhan OJha From: Rishabh Agrawal [mailto:rishabh.agra...@impetus.co.in] Sent: Monday, January 28, 2013 12:16 PM To: user@cassandra.apache.org Subject: Accessing Metadata of Column Familes Hello, I wish to access metadata information on column families. How can I do it? Any ideas? Thanks and Regards Rishabh Agrawal NOTE: This message may contain information that is confidential, proprietary, privileged or otherwise protected by law. The message is intended solely for the named addressee. If received in error, please destroy and notify the sender. Any use of this email is prohibited when received in error. Impetus does not represent, warrant and/or guarantee, that the integrity of this communication has been maintained nor that the communication is free of errors, virus, interception or interference. The contents of this email, including the attachments, are PRIVILEGED AND CONFIDENTIAL to the intended recipient at the email address to which it has been addressed. If you receive it in error, please notify the sender immediately by return email and then permanently delete it from your system. The unauthorized use, distribution, copying or alteration of this email, including the attachments, is strictly forbidden. Please note that neither MakeMyTrip nor the sender accepts any responsibility for viruses and it is your responsibility to scan the email and attachments (if any). No contracts may be concluded on behalf of MakeMyTrip by means of email communications. NOTE: This message may contain information that is confidential, proprietary, privileged or otherwise protected by law. The message is intended solely for the named addressee. If received in error, please destroy and notify the sender. Any use of this email is prohibited when received in error. Impetus does not represent, warrant and/or guarantee, that the integrity of this communication has been maintained nor that the communication is free of errors, virus, interception or interference. The contents of this email, including the attachments, are PRIVILEGED AND CONFIDENTIAL to the intended recipient at the email address to which it has been addressed. If you receive it in error, please notify the sender immediately by return email and then permanently delete it from your system. The unauthorized use, distribution, copying or alteration of this email, including the attachments, is strictly forbidden. Please note that neither MakeMyTrip nor the sender accepts any responsibility for viruses and it is your responsibility to scan the email and attachments (if any). No contracts may be concluded on behalf of MakeMyTrip by means of email communications.
