Can you help try one more thing if you can?

Run jstack on the foreman Drillbit process while the query is doing
the query planning. Capture the jstack every one second or couple of
seconds consecutively for some time, by appending the jstack output
into one log file. Take a look at the stack trace for the forman
thread in the form of "275b623b-bb15-8bd8-fd29-f9a571a7534e:foreman"
(The first part is the query ID).  If foreman thread is stuck in one
method call, it  may show up in the log repeatedly.  In this way we
may have a better idea what's the cause of the problem.

Based on the tests you tried, the combination of the query / parquet
files probably hit a bug in the code that we are not aware of
currently. Without the parquet files to re-reproduce, it's hard to
debug the issue and find a possible fix.



On Wed, Feb 15, 2017 at 8:35 AM, David Kincaid <[email protected]> wrote:
> I ran that EXPLAIN that you suggested against the entire 100 file table and
> it takes about 3 seconds. I will try to get a defect written up in the next
> few days.
>
> - Dave
>
> On Tue, Feb 14, 2017 at 9:06 PM, Jinfeng Ni <[email protected]> wrote:
>
>> From the two tests you did, I'm inclined to think there might be some
>> special things in your parquet files. How do you generate these
>> parquet files? Do they contain normal data type (int/float/varchar),
>> or complex type (array/map)?
>>
>> In our environment, we also have hundreds of parquet files, each with
>> size ~ hundreds of MBs.  A typical query (several tables joined) would
>> takes a couple of seconds in planning.
>>
>> One more test if you can help run.
>>
>> EXPLAIN PLAN FOR
>> SELECT someCol1, someCol2
>> FROM dfs.`parquet/transaction/OneSingleFile.parquet`;
>>
>> The above query is simple enough that planner should not spend long
>> time in enumerating different choices. If it still takes long time for
>> query planning,  the more likely cause might be in parquet files you
>> used.
>>
>>
>>
>> On Tue, Feb 14, 2017 at 1:06 PM, David Kincaid <[email protected]>
>> wrote:
>> > I will write up a defect. The first test you suggested below - running
>> the
>> > query on just one of our Parquet files produces the same result (10-12
>> > minute planning time). However, the second test - using
>> > cp.`tpch/nation.parquet` - results in a planning time of only about a
>> > minute. So, I'm not sure how to interpret that. What does that mean to
>> you
>> > all?
>> >
>> > - Dave
>> >
>> > On Tue, Feb 14, 2017 at 12:37 PM, Jinfeng Ni <[email protected]> wrote:
>> >
>> >> Normally, the slow query planning could be caused by :
>> >>
>> >> 1. Some planner rule hit a bug when processing certain operators in
>> >> the query, for instance join operator, distinct aggregate.  The query
>> >> I tried on a small file seems to rule out this possibility.
>> >> 2. The parquet metadata access time. According to the long, this does
>> >> not seem to be the issue.
>> >> 3. Something we are not aware of.
>> >>
>> >> To help get some clue, can you help do the following:
>> >> 1. run the query over one single parquet files, in stead of 100
>> >> parquet files? You can change using
>> >> dfs.`parquet/transaction/OneSingleFile.parquet`. I'm wondering if the
>> >> planning time is proportional to # of parquet files.
>> >>
>> >> 2. What if you try your query by replacing
>> >> dfs.`parquet/transaction/OneSingleFile.parquet` with
>> >> cp.`tpch/nation.parquet` which is a small tpch parquet file (you need
>> >> re-enable the storage plugin 'cp')? Run EXPLAIN should be fine. This
>> >> will tell us if the problem is caused by the parquet source, or the
>> >> query itself.
>> >>
>> >> Yes, please create a defect in Drill JIRA.
>> >>
>> >> On Tue, Feb 14, 2017 at 5:02 AM, David Kincaid <[email protected]>
>> >> wrote:
>> >> > Thank you for the feedback. It seems there is nothing more I can do
>> on my
>> >> > end. What are my next steps? Shall I create a defect in the Drill
>> Jira?
>> >> >
>> >> > - Dave
>> >> >
>> >> > On Mon, Feb 13, 2017 at 5:13 PM, Jinfeng Ni <[email protected]> wrote:
>> >> >
>> >> >> The size of parquet files will matter in terms of meta data access
>> >> >> time, which is just 212 ms according to your log file. My
>> >> >> understanding is it does not matter too much to the overall planning
>> >> >> times. That's why it probably makes sense to try over such a small
>> toy
>> >> >> example.
>> >> >>
>> >> >> Normally the planning time for such simple query should be much
>> >> >> shorter than 12 minutes.  It indicates it could be caused by a code
>> >> >> bug, or something else that we are currently unaware of.
>> >> >>
>> >> >>
>> >> >>
>> >> >>
>> >> >>
>> >> >>
>> >> >> On Mon, Feb 13, 2017 at 2:47 PM, David Kincaid <
>> [email protected]>
>> >> >> wrote:
>> >> >> > The example in DRILL-5183 is just a very small toy example to
>> >> demonstrate
>> >> >> > the bug with how Drill reads Parquet array fields. It doesn't have
>> >> >> anything
>> >> >> > to do with this planning issue (at least I don't think it does).
>> Sorry
>> >> >> if I
>> >> >> > confused things with that reference.
>> >> >> >
>> >> >> > I just tried running our query directly against the table at
>> >> >> > dfs.`parquet/transaction` and get the same result (12 minutes of
>> >> planning
>> >> >> > time). I disabled the cp and s3 storage plugins that were enabled
>> so
>> >> that
>> >> >> > only the dfs storage plugin is enabled and the result is the same.
>> >> >> >
>> >> >> > Is this expected for Drill to take this long in the planning phase
>> >> for a
>> >> >> > query? Is there anything else I can try or information I could
>> >> provide to
>> >> >> > help identify the bug (seems like a bug to me)? I really appreciate
>> >> you
>> >> >> > guys helping out so quickly this afternoon.
>> >> >> >
>> >> >> > - Dave
>> >> >> >
>> >> >> > On Mon, Feb 13, 2017 at 4:13 PM, Jinfeng Ni <[email protected]>
>> wrote:
>> >> >> >
>> >> >> >> I downloaded books.parquet from DRILL-5183, and created a view on
>> top
>> >> >> >> of this single parquet file. Then, run EXPLAIN for the query, and
>> it
>> >> >> >> completes within 1.2 seconds on Drill 1.8.0 release. (The # of
>> >> parquet
>> >> >> >> files would impact the time to fetch metadata. Since it's not the
>> >> >> >> bottleneck in this case, it should not cause a big difference).
>> >> >> >>
>> >> >> >> Do you see the long planning time issue for this query only, or it
>> >> >> >> happens for other queries as well? Besides the possibility of
>> >> planning
>> >> >> >> rule bugs, we once saw another possible cause of long planning
>> issue.
>> >> >> >> In your storage plugin configuration, if you enable some other
>> >> storage
>> >> >> >> plugin (for instance, hbase, or hive etc) which are slow to
>> access,
>> >> >> >> then those un-relevant storage plugin might impact your query as
>> >> well.
>> >> >> >> You may temporarily disable those storage plugins, and see if it's
>> >> the
>> >> >> >> cause of the problem.
>> >> >> >>
>> >> >> >> 0: jdbc:drill:zk=local> explain plan for
>> >> >> >> . . . . . . . . . . . > select fltb1.sapId, yearmo,
>> >> >> >> . . . . . . . . . . . > COUNT(*) as totalcnt,
>> >> >> >> . . . . . . . . . . . > count(distinct(CASE
>> >> >> >> . . . . . . . . . . . >                WHEN
>> >> >> >> . . . . . . . . . . . >                (REPEATED_CONTAINS(fltb1.
>> >> >> >> classLabels,
>> >> >> >> . . . . . . . . . . . >
>> >> >> >> 'Thing:Service:MedicalService:Diagnostic:Radiology:
>> Ultrasound.*'))
>> >> >> >> . . . . . . . . . . . >                THEN fltb1.invoiceId
>> >> >> >> . . . . . . . . . . . >                END)) as ultracount,
>> >> >> >> . . . . . . . . . . . > count(distinct (CASE
>> >> >> >> . . . . . . . . . . . >                 WHEN
>> >> >> >> . . . . . . . . . . . >                 (REPEATED_CONTAINS(fltb1.
>> >> >> >> classLabels,
>> >> >> >> . . . . . . . . . . . >
>> >> >> >> 'Thing:Service:MedicalService:Diagnostic:LaboratoryTest.*'))
>> >> >> >> . . . . . . . . . . . >                 THEN fltb1.invoiceId
>> >> >> >> . . . . . . . . . . . >                 END)) as labcount
>> >> >> >> . . . . . . . . . . . > from (
>> >> >> >> . . . . . . . . . . . >   select sapid, invoiceId,
>> >> >> >> . . . . . . . . . . . >         TO_CHAR(TO_TIMESTAMP(
>> >> transactionDate,
>> >> >> >> 'YYYY-MM-dd HH:mm:ss.SSSSSS'), 'yyyy-MM') yearmo,
>> >> >> >> . . . . . . . . . . . >         classLabels
>> >> >> >> . . . . . . . . . . . >       from dfs.tmp.transactionView) fltb1
>> >> >> >> . . . . . . . . . . . > group by fltb1.sapId, yearmo;
>> >> >> >> +------+------+
>> >> >> >> | text | json |
>> >> >> >> +------+------+
>> >> >> >> | 00-00    Screen
>> >> >> >> 00-01      Project(sapId=[$0], yearmo=[$1], totalcnt=[$2],
>> >> >> >> ultracount=[$3], labcount=[$4])
>> >> >> >> ....................................
>> >> >> >> 00-09                SelectionVectorRemover
>> >> >> >> 00-12                  Sort(sort0=[$0], sort1=[$1], dir0=[ASC],
>> >> >> dir1=[ASC])
>> >> >> >> 00-15                    HashAgg(group=[{0, 1}],
>> totalcnt=[COUNT()])
>> >> >> >> ................................
>> >> >> >> 00-22                          Scan(groupscan=[ParquetGroupScan
>> >> >> >> [entries=[ReadEntryWithPath [path=file:/tmp/parquet/
>> transaction]],
>> >> >> >> selectionRoot=file:/tmp/parquet/transaction, numFiles=1,
>> >> >> >> usedMetadataFile=false, columns=[`sapId`, `invoiceId`,
>> >> >> >> `transactionDate`, `classLabels`.`array`]]])
>> >> >> >>
>> >> >> >> 1 row selected (1.195 seconds)
>> >> >> >>
>> >> >> >>
>> >> >> >> On Mon, Feb 13, 2017 at 1:51 PM, David Kincaid <
>> >> [email protected]>
>> >> >> >> wrote:
>> >> >> >> > Here is the entire transactionView.view.drill file. As you can
>> see
>> >> the
>> >> >> >> view
>> >> >> >> > itself is very simple and is just wrapping a syntactic problem
>> with
>> >> >> the
>> >> >> >> > array field. That's an issue I reported in Jira under
>> DRILL-5183 (
>> >> >> >> > https://issues.apache.org/jira/browse/DRILL-5183)
>> >> >> >> >
>> >> >> >> > {
>> >> >> >> >   "name" : "transactionView",
>> >> >> >> >   "sql" : "SELECT `transactionRowKey`, `sapId`, `practiceName`,
>> >> >> >> > `practiceCity`, `practiceState`, `practicePostalCode`,
>> `animalId`,
>> >> >> >> > `dateOfBirth`, `species`, `breed`, `gender`, `status`,
>> `ownerId`,
>> >> >> >> > `itemType`, `classification`, `subclass`, `practiceDescription`,
>> >> >> >> > `clientDescription`, `invoiceId`, `unitOfMeasure`, `vendorName`,
>> >> >> >> `vaccine`,
>> >> >> >> > `rabies`, `vaccineType`, `price`, `quantity`, `transactionDate`,
>> >> >> >> > `visitReason`, `speciesCode`, `genderCode`,
>> >> >> `t`.`classLabels`['array'] AS
>> >> >> >> > `classLabels`\nFROM `dfs`.`/parquet/transaction` AS `t`",
>> >> >> >> >   "fields" : [ {
>> >> >> >> >     "name" : "transactionRowKey",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "sapId",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "practiceName",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "practiceCity",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "practiceState",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "practicePostalCode",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "animalId",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "dateOfBirth",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "species",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "breed",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "gender",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "status",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "ownerId",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "itemType",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "classification",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "subclass",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "practiceDescription",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "clientDescription",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "invoiceId",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "unitOfMeasure",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "vendorName",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "vaccine",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "rabies",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "vaccineType",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "price",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "quantity",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "transactionDate",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "visitReason",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "speciesCode",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "genderCode",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   }, {
>> >> >> >> >     "name" : "classLabels",
>> >> >> >> >     "type" : "ANY",
>> >> >> >> >     "isNullable" : true
>> >> >> >> >   } ],
>> >> >> >> >   "workspaceSchemaPath" : [ ]
>> >> >> >> > }
>> >> >> >> >
>> >> >> >> > On Mon, Feb 13, 2017 at 3:47 PM, Jinfeng Ni <[email protected]>
>> >> wrote:
>> >> >> >> >
>> >> >> >> >> Yes, the log confirmed that the planning, especially physical
>> >> >> >> >> planning, is the one that took most of the time.
>> >> >> >> >>
>> >> >> >> >> If the definition of view s3.cisexport.transactionView is not
>> very
>> >> >> >> >> complicated (involves large # of tables), then it's possible
>> that
>> >> >> some
>> >> >> >> >> planner rules have a bug. (In the past, we once saw couple of
>> >> planner
>> >> >> >> >> rules would be fired in a loop).
>> >> >> >> >>
>> >> >> >> >> Is it possible that you can share the DDL of the view?  That
>> may
>> >> help
>> >> >> >> >> us re-produce the problem and take a look at the trace of
>> Calcite,
>> >> >> >> >> which Drill uses as the query planner.
>> >> >> >> >>
>> >> >> >> >>
>> >> >> >> >>
>> >> >> >> >>
>> >> >> >> >>
>> >> >> >>
>> >> >>
>> >>
>>

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