Hello,
I have created a column family for User File Management.
CREATE TABLE "UserFile" ("USERID" bigint,"FILEID" text,"FILETYPE"
int,"FOLDER_UID" text,"FILEPATHINFO" text,"JSONCOLUMN" text,PRIMARY KEY
("USERID","FILEID"));
Sample Entry
(4*************003, 3f9**************************6a1, null, 2 ,
[{"FOLDER_TYPE":"-1","UID":"1","FOLDER":"\"HOME\""}]
,{"filename":"untitled","size":1,"kind":-1,"where":""})
Queries :
Select "USERID","FILEID","FILETYPE","FOLDER_UID","JSONCOLUMN" from "UserFile"
where "USERID"=<value> and "FILEID" in (<value>,<value>,...)
Select "USERID","FILEID","FILEPATHINFO" from "UserFile" where
"USERID"=<value> and "FILEID" in (<value>,<value>,...)
This column family was perfectly working in our lab. I was able to fetch the
results for the queries stated at less than 10ms. I deployed this in
production(Cassandra 2.1.13), It was working perfectly for a month or two. But
now at times the queries are taking 5s to 10s. On analysing further, I found
that few users are deleting the files too frequently. This generates too many
tombstones. I have set the gc_grace_seconds to the default 10 days and I have
chosen SizeTieredCompactionStrategy. I want to optimise this Data Model for
read efficiency.
Any help is much appreciated.
Best Regards,
Julian.
