Re: Mixing LWT and normal operations for a partition
Hi, *1. The below sequence of commands also does not appear to give an expected output.* Since, there is a delete command in the batch and then an LWT update using IF EXISTS, in the final result row with id = 5 must get deleted. cassandra@cqlsh> select * from demo.tweets; *id* | *body* | *latitude* | *longitude* | *time* | *user* +--+--+---+-+--- *5* | *old body* | *32.6448* | *78.21672* | *2019-01-14 18:30:00.00+* | *user5* (1 rows) cassandra@cqlsh> cassandra@cqlsh> begin batch update demo.tweets SET body='new body' where id = 5 IF EXISTS; delete from demo.tweets where id = 5 IF EXISTS; apply batch; *[applied]* --- *True* cassandra@cqlsh> select * from demo.tweets; *id* | *body* | *latitude* | *longitude* | *time* | *user* +--+--+---+--+-- *5* | *new body* | *null* | *null* | *null* | *null* (1 rows) cassandra@cqlsh> *2. On the contrary below sequence of commands gives the expected output:* cassandra@cqlsh> insert into demo.tweets (id, user, body, time, latitude, longitude) values (5, 'user5', 'old body', '2019-01-15', 32.644800, 78.216721); cassandra@cqlsh> cassandra@cqlsh> select * from demo.tweets; *id* | *body* | *latitude* | *longitude* | *time* | *user* +--+--+---+-+--- *5* | *old body* | *32.6448* | *78.21672* | *2019-01-14 18:30:00.00+* | *user5* (1 rows) cassandra@cqlsh> delete from demo.tweets where id = 5 IF EXISTS; *[applied]* --- *True* cassandra@cqlsh> select * from demo.tweets; *id* | *body* | *latitude* | *longitude* | *time* | *user* +--+--+---+--+-- (0 rows) cassandra@cqlsh> update demo.tweets SET body='new body' where id = 5 IF EXISTS; *[applied]* --- *False* cassandra@cqlsh> select * from demo.tweets; *id* | *body* | *latitude* | *longitude* | *time* | *user* +--+--+---+--+-- (0 rows) Thanks Shaurya On Fri, May 3, 2019 at 1:02 AM Shaurya Gupta wrote: > One suggestion - I think Cassandra community is already having a drive to > update the documentation. This could be added to CQLSH documentation or > some other relevant documentation. > > On Fri, May 3, 2019 at 12:56 AM Shaurya Gupta > wrote: > >> Thanks Jeff. >> >> On Fri, May 3, 2019 at 12:38 AM Jeff Jirsa wrote: >> >>> No. Don’t mix LWT and normal writes. >>> >>> -- >>> Jeff Jirsa >>> >>> >>> > On May 2, 2019, at 11:43 AM, Shaurya Gupta >>> wrote: >>> > >>> > Hi, >>> > >>> > We are seeing really odd behaviour while try to delete a row which is >>> simultaneously being updated in a light weight transaction. >>> > The delete command succeeds and the LWT update fails with timeout >>> exception but still the next select statement shows that the row still >>> exists. This occurs ones in many such scenarios. >>> > >>> > Is it fine to mix LWT and normal operations for the same partition? Is >>> it expected to work? >>> > >>> > Thanks >>> > Shaurya >>> >>> - >>> To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org >>> For additional commands, e-mail: user-h...@cassandra.apache.org >>> >>> >> >> -- >> Shaurya Gupta >> >> >> > > -- > Shaurya Gupta > > > -- Shaurya Gupta
Re: Mixing LWT and normal operations for a partition
One suggestion - I think Cassandra community is already having a drive to update the documentation. This could be added to CQLSH documentation or some other relevant documentation. On Fri, May 3, 2019 at 12:56 AM Shaurya Gupta wrote: > Thanks Jeff. > > On Fri, May 3, 2019 at 12:38 AM Jeff Jirsa wrote: > >> No. Don’t mix LWT and normal writes. >> >> -- >> Jeff Jirsa >> >> >> > On May 2, 2019, at 11:43 AM, Shaurya Gupta >> wrote: >> > >> > Hi, >> > >> > We are seeing really odd behaviour while try to delete a row which is >> simultaneously being updated in a light weight transaction. >> > The delete command succeeds and the LWT update fails with timeout >> exception but still the next select statement shows that the row still >> exists. This occurs ones in many such scenarios. >> > >> > Is it fine to mix LWT and normal operations for the same partition? Is >> it expected to work? >> > >> > Thanks >> > Shaurya >> >> - >> To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org >> For additional commands, e-mail: user-h...@cassandra.apache.org >> >> > > -- > Shaurya Gupta > > > -- Shaurya Gupta
Re: Mixing LWT and normal operations for a partition
Thanks Jeff. On Fri, May 3, 2019 at 12:38 AM Jeff Jirsa wrote: > No. Don’t mix LWT and normal writes. > > -- > Jeff Jirsa > > > > On May 2, 2019, at 11:43 AM, Shaurya Gupta > wrote: > > > > Hi, > > > > We are seeing really odd behaviour while try to delete a row which is > simultaneously being updated in a light weight transaction. > > The delete command succeeds and the LWT update fails with timeout > exception but still the next select statement shows that the row still > exists. This occurs ones in many such scenarios. > > > > Is it fine to mix LWT and normal operations for the same partition? Is > it expected to work? > > > > Thanks > > Shaurya > > - > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > For additional commands, e-mail: user-h...@cassandra.apache.org > > -- Shaurya Gupta
Re: Mixing LWT and normal operations for a partition
No. Don’t mix LWT and normal writes. -- Jeff Jirsa > On May 2, 2019, at 11:43 AM, Shaurya Gupta wrote: > > Hi, > > We are seeing really odd behaviour while try to delete a row which is > simultaneously being updated in a light weight transaction. > The delete command succeeds and the LWT update fails with timeout exception > but still the next select statement shows that the row still exists. This > occurs ones in many such scenarios. > > Is it fine to mix LWT and normal operations for the same partition? Is it > expected to work? > > Thanks > Shaurya - To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org For additional commands, e-mail: user-h...@cassandra.apache.org
Mixing LWT and normal operations for a partition
Hi, We are seeing really odd behaviour while try to delete a row which is simultaneously being updated in a light weight transaction. The delete command succeeds and the LWT update fails with timeout exception but still the next select statement shows that the row still exists. This occurs ones in many such scenarios. Is it fine to mix LWT and normal operations for the same partition? Is it expected to work? Thanks Shaurya
