Rereading your post, I think there is some concern between embedded/single drillbit mode, and distributed mode.
When you run multiple drillbits in distributed mode, you will (should) be enabling authentication. Thus each user will log in to "a" drill bit. There is no concern on which one, it's not the only one doing the work, You could have two users on the same drill bit, or on different bits. The "System" options will be set by default for all users on logon and at this point, a session for the user is created. You can see what the current options for that user is with "Select * from sys.options" If you are a user who is in the administrative group (security.admin.users in select * from sys.options) then you can use ALTER SYSTEM set `somekey` = `someval` And that will set the default option for all users when they logon. A user can use ALTER SESSION set `somekey = `someval` To alter what say their store.format is. So User 1 can authentication and connect to Drillbit 1 or 2, and set store.format (at the session level) to parquet and user 2 can logon it Drillbit 1 or 2 (doesn't matter, even if user 1 is logged into the same drill bit with a different store.format) and set it to csv. I think the key here is authenticated distributed mode in Drill and that will be how you will do what you need to do. John On Tue, Sep 4, 2018 at 7:30 PM, John Omernik <[email protected]> wrote: > The session is the users session, not the drill bit. Since you are > connected to a specific drill bit, when you alter session it will work. Try > to use session stickiness or pinning on your HA solution and you will be > go. With my DNS round robin it picks a "connecting" drill bit and sticks to > it until the session is done. The settings apply to the drill cluster while > in distributed mode. > > On Tue, Sep 4, 2018 at 3:56 PM, Joe Auty <[email protected]> wrote: > >> Thanks for your response John! >> >> We are using Drill both in an ETL context, as well as for general >> warehouse queries. One Drill user uses store format set to Parquet while >> the other uses store format set to CSV to read and write from HDFS. We are >> currently using Kubernetes Services rather than DNS round robin, but we >> only have one drillbit in the cluster while we try to sort out this issue. >> >> I'm not clear though how alter session would work with a session with >> multiple drillbits involved? We need to ensure that the right store format >> option is set, so like I said we are using different Drill usernames and >> sessions to accommodate this, but how would alter session commands apply to >> preserve these different settings across multiple drillbits? >> >> >> >> >> >> >> John Omernik wrote on 2018-09-04 2:48 PM: >> >>> Are these ETL ish type queries? store.format should only apply when >>> Drill >>> is writing data, when it is reading, it uses the filenames and other >>> hints >>> to read. >>> >>> Thus, if you do HA, say with DNS (like like in the other thread) and >>> prior >>> to running your CREATE TABLE AS (I Am assuming this is what you are >>> doing) >>> you can do ALTER SESSION set store.format = 'parquet' >>> >>> Instead of setting the ALTER SYSTEM, you can use ALTER SESSION so it only >>> applies to the current session, regardless of foreman. >>> >>> John >>> >>> >>> On Tue, Sep 4, 2018 at 1:00 PM, Joe Auty <[email protected]> wrote: >>> >>> Hello, >>>> >>>> We need to have some queries executed with store.format set to parquet >>>> and >>>> some with this option set to CSV. To date we have experimented with >>>> setting >>>> the store format for sessions controlled by using two separate user >>>> logins >>>> as a sort of context switch, but I'm wondering if the group here might >>>> have >>>> suggestions for a better way to handle this, particularly one that will >>>> scale a little better for us? >>>> >>>> The main problem we have with this approach is in introducing multiple >>>> drillbits/HA and assuring that the session and the settings we need are >>>> respected across all drillbits (whether with an HAProxy + sticky session >>>> approach or any other approach). There is a more general thread (which >>>> I've >>>> chosen not to hijack) about HA Drill from a more general standpoint, you >>>> might think of my question here as being similar, but with the need for >>>> a >>>> context switch to support multiple Drill configurations/session options. >>>> >>>> Here are the various attempts and approaches we have come up with so >>>> far. >>>> I'm wondering if you'd have any general advice as to which approach >>>> would >>>> be best for us to take, considering future plans for Drill itself. For >>>> example, if need be we can write our own plugin(s) if this is the >>>> smartest >>>> approach: >>>> >>>> - embedded the store.format option into the query itself by chaining >>>> multiple queries together separated by a comma (it appears that this >>>> doesn't work at all) >>>> - look into writing some sort of plugin to allow us to scale our current >>>> approach somehow (I realize that this is vague) >>>> - a "foreman" approach where we stick with our current approach and >>>> direct >>>> all requests to our "foreman"/master with the hope and expectation that >>>> it >>>> will farm out work to the workers/slaves >>>> - multiple clusters set with different settings >>>> >>>> Each of these approaches seems to have its pros and cons. To reiterate: >>>> what approach do you think would be the smartest and most future-proof >>>> approach for us to take? >>>> >>>> Thanks in advance! >>>> >>>> >> >
