Commit Graph

44 Commits

Author SHA1 Message Date
Katya Macedo a2be685824
Remove the time bit, fix headings (#12808)
* Remove the time bit, fix headings

* Adopt review suggestions

* Edits

* Update smoosh file description

* Adopt review suggestions

* Update spelling
2022-07-20 15:37:57 -07:00
Jill Osborne f050069767
Segments doc update (#12344)
* Corrected heading levels in segments doc

* IMPLY-18394: Updated Segments doc

* Update docs/design/segments.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/segments.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/segments.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/segments.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/segments.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/segments.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update segments.md

* Updated links to changed headings in Segments doc

* Corrected spelling error

* Update segments.md

Incorporated suggestions from Paul Rogers.

* Update index.md

* Update segments.md

* Update segments.md

* Update segments.md

* Update compaction.md

* Update docs/design/segments.md

fix typo

* Update docs/ingestion/compaction.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/design/segments.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/design/segments.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/design/segments.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/design/segments.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/design/segments.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/design/segments.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/design/segments.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/design/segments.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/design/segments.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/design/segments.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/design/segments.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

Co-authored-by: Charles Smith <techdocsmith@gmail.com>
Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>
2022-06-16 13:25:17 -07:00
Victoria Lim 94564b6ce6
Update screenshots for Druid console doc (#12593)
* druid console doc updates

* remove extra image

* Apply suggestions from code review

Co-authored-by: Katya Macedo  <38017980+ektravel@users.noreply.github.com>

* Apply suggestions from code review

* Apply suggestions from code review

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* updated screenshot labels

Co-authored-by: Katya Macedo  <38017980+ektravel@users.noreply.github.com>
Co-authored-by: Charles Smith <techdocsmith@gmail.com>
2022-06-15 16:42:20 -07:00
Victoria Lim 353475bd36
Docs for automatic compaction (#12569)
* docs for auto-compaction

* fix broken links

* another link

* Apply suggestions from code review

Co-authored-by: Suneet Saldanha <suneet@apache.org>

* Apply suggestions from code review

Co-authored-by: Suneet Saldanha <suneet@apache.org>

* Apply suggestions from code review

Co-authored-by: Charles Smith <techdocsmith@gmail.com>
Co-authored-by: Suneet Saldanha <suneet@apache.org>

* reorg content for skipOffset

* Update docs/ingestion/automatic-compaction.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Apply suggestions from code review

Co-authored-by: Kashif Faraz <kashif.faraz@gmail.com>

Co-authored-by: Suneet Saldanha <suneet@apache.org>
Co-authored-by: Charles Smith <techdocsmith@gmail.com>
Co-authored-by: Kashif Faraz <kashif.faraz@gmail.com>
2022-06-09 14:55:12 -07:00
Victoria Lim 0206a2da5c
Update automatic compaction docs with consistent terminology (#12416)
* specify automatic compaction where applicable

* Apply suggestions from code review

Co-authored-by: Katya Macedo  <38017980+ektravel@users.noreply.github.com>

* update for style and consistency

* implement suggested feedback

* remove duplicate example

* Apply suggestions from code review

Co-authored-by: Katya Macedo  <38017980+ektravel@users.noreply.github.com>

* Update docs/ingestion/compaction.md

Co-authored-by: Katya Macedo  <38017980+ektravel@users.noreply.github.com>

* Update docs/operations/api-reference.md

* update .spelling

* Adopt review suggestions

Co-authored-by: Katya Macedo  <38017980+ektravel@users.noreply.github.com>
2022-05-03 16:22:25 -07:00
Peter Marshall 5167d328b1
Docs - query caching (#11584)
* Update caching.md

Knowledge from https://the-asf.slack.com/archives/CJ8D1JTB8/p1597781107153900

Update caching.md

A few additional updates OTBO https://the-asf.slack.com/archives/CJ8D1JTB8/p1608669046041300

* Update caching.md

Typos

* Amendments on the segment cache

Significant updates on content around the segment cache, pull process, and in-memory cache

* Update docs/design/historical.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/historical.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/historical.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/historical.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/historical.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/historical.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/querying/caching.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/querying/caching.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/querying/caching.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/querying/caching.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/historical.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/historical.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/design/historical.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/operations/basic-cluster-tuning.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/querying/caching.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/querying/caching.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/querying/caching.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/querying/caching.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/querying/caching.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update docs/operations/basic-cluster-tuning.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Update basic-cluster-tuning.md

typo

* Update docs/querying/caching.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

* Whole-query caching update

Made more succinct and removed specific config to change.

* Update docs/design/historical.md

Co-authored-by: Charles Smith <techdocsmith@gmail.com>
2022-04-18 17:00:21 +08:00
Maytas Monsereenusorn 6e2eded277
Allow coordinator run auto compaction duty period to be configured separately from other indexing duties (#12263)
* add impl

* add impl

* add unit tests

* add impl

* add impl

* add serde test

* add tests

* add docs

* fix test

* fix test

* fix docs

* fix docs

* fix spelling
2022-02-18 23:02:57 -08:00
Victoria Lim c61b19d443
Refactor SQL docs (#12239)
* refactor and link fixes

* add sql docs to left nav

* code format for needle

* updated web console script

* link fixes

* update earliest/latest functions

* edits for grammar and style

* more link fixes

* another link

* update with #12226

* update .spelling file
2022-02-11 14:43:30 -08:00
Kashif Faraz 6607e4cc75
Docs: Remove reference to deprecated field `targetPartitionSize` (#11974)
* Remove reference to deprecated field `targetPartitionSize`

* Fix spelling of LeaderLatch
2021-11-23 15:32:16 +05:30
Jian Wang 8e7e679984
Add more metrics for Jetty server thread pool usage (#11113)
Add more metrics for jetty server thread pool usage so we know if we have allocated enough http threads to handle requests.
2021-11-07 16:51:44 +05:30
Katya Macedo 5e1dc843d1
Fix quickstart link (#11864) 2021-11-02 13:27:53 +08:00
sthetland d02d2d9d56
Design/architecture doc touchups (#11762)
* rearrange design content

* casing consistency

Co-authored-by: Charles Smith <techdocsmith@gmail.com>
2021-10-04 11:09:35 -07:00
Kashif Faraz c641657bae
Fix router documentation for `druid.router.sql.enable` (#11716)
* Rename field, fix router documentation

* Add more lines to doc

* Apply doc suggestions from code review

Co-authored-by: Charles Smith <techdocsmith@gmail.com>

Co-authored-by: Charles Smith <techdocsmith@gmail.com>
2021-09-28 22:54:13 +05:30
Clint Wylie ec334a641b
MySQL extension with MariaDB connector docs (#11608)
* add docs for mariadb support via mysql extensions

* add logging so you know what druid knows

* homogenize

* spelling

* missed a couple
2021-08-19 01:52:26 -07:00
Charles Smith 6524d838d7
Docs refactor of ingestion. Carries #11541 (#11576)
* Docs refactor of ingestion. Carries #11541

* Update docs/misc/math-expr.md

* add Apache license

* fix header, add topics to sidebar

* Update docs/ingestion/partitioning.md

* pick up changes to  and  md from c7fdf1d, #11479

Co-authored-by: Suneet Saldanha <suneet@apache.org>
Co-authored-by: Jihoon Son <jihoonson@apache.org>
2021-08-13 08:42:03 -07:00
Kashif Faraz aaf0aaad8f
Enable routing of SQL queries at Router (#11566)
This PR adds a new property druid.router.sql.enable which allows the
Router to handle SQL queries when set to true.

This change does not affect Avatica JDBC requests and they are still routed
by hashing the Connection ID.

To allow parsing of the request object as a SqlQuery (contained in module druid-sql),
some classes have been moved from druid-server to druid-services with
the same package name.
2021-08-13 18:44:39 +05:30
Paul Rogers 3e7cba738f
Minor edits to architecture page to improve flow (#11465)
* Minor edits to architecture page to improve flow

* Fixed spelling issue
2021-08-09 07:48:29 -07:00
Kashif Faraz 8a4e27f51d
Select broker based on query context parameter `brokerService` (#11495)
This change allows the selection of a specific broker service (or broker tier) by the Router.

The newly added ManualTieredBrokerSelectorStrategy works as follows:

Check for the parameter brokerService in the query context. If this is a valid broker service, use it.
Check if the field defaultManualBrokerService has been set in the strategy. If this is a valid broker service, use it.
Move on to the next strategy
2021-07-27 20:56:05 +05:30
Charles Smith cf2cde1d2d
add links to release notes, light refactor of landing page (#11051)
* add links to release notes, light refactor of landing page

* Update docs/design/index.md
2021-05-07 14:26:47 -07:00
sthetland ca1412d574
Reduce visibility of Tranquility documentation (#11134)
* reduce visibility of tranquility doc

Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
2021-05-03 16:48:24 -07:00
Jeet Patel 31042cddf5
Fix `defaultMetricDimensions.json` path link (#11156) 2021-04-24 11:08:03 +08:00
sthetland 6ae8059c09
cleaning up and fixing links (#10528)
* cleaning up and fixing links

* reverting local link

* Update indexer.md

* link checking

* Fixing one more stale link for PostgreSQL
2020-12-17 13:37:43 -08:00
Gian Merlino 96a387d972
Fixes and tests related to the Indexer process. (#10631)
* Fixes and tests related to the Indexer process.

Three bugs fixed:

1) Indexers would not announce themselves as segment servers if they
   did not have storage locations defined. This used to work, but was
   broken in #9971. Fixed this by adding an "isSegmentServer" method
   to ServerType and updating SegmentLoadDropHandler to always announce
   if this method returns true.

2) Certain batch task types were written in a way that assumed "isReady"
   would be called before "run", which is not guaranteed. In particular,
   they relied on it in order to initialize "taskLockHelper". Fixed this
   by updating AbstractBatchIndexTask to ensure "isReady" is called
   before "run" for these tasks.

3) UnifiedIndexerAppenderatorsManager did not properly handle complex
   datasources. Introduced DataSourceAnalysis in order to fix this.

Test changes:

1) Add a new "docker-compose.cli-indexer.yml" config that spins up an
   Indexer instead of a MiddleManager.

2) Introduce a "USE_INDEXER" environment variable that determines if
   docker-compose will start up an Indexer or a MiddleManager.

3) Duplicate all the jdk8 tests and run them in both MiddleManager and
   Indexer mode.

4) Various adjustments to encourage fail-fast errors in the Docker
   build scripts.

5) Various adjustments to speed up integration tests and reduce memory
   usage.

6) Add another Mac-specific approach to determining a machine's own IP.
   This was useful on my development machine.

7) Update segment-count check in ITCompactionTaskTest to eliminate a
   race condition (it was looking for 6 segments, which only exist
   together briefly, until the older 4 are marked unused).

Javadoc updates:

1) AbstractBatchIndexTask: Added javadocs to determineLockGranularityXXX
   that make it clear when taskLockHelper will be initialized as a side
   effect. (Related to the second bug above.)

2) Task: Clarified that "isReady" is not guaranteed to be called before
   "run". It was already implied, but now it's explicit.

3) ZkCoordinator: Clarified deprecation message.

4) DataSegmentServerAnnouncer: Clarified deprecation message.

* Fix stop_cluster script.

* Fix sanity check in script.

* Fix hashbang lines.

* Test and doc adjustments.

* Additional tests, and adjustments for tests.

* Split ITs back out.

* Revert change to druid_coordinator_period_indexingPeriod.

* Set Indexer capacity to match MM.

* Bump up Historical memory.

* Bump down coordinator, overlord memory.

* Bump up Broker memory.
2020-12-08 16:02:26 -08:00
Antoine Huret 88d20a61a6
renamed authenticationChain to authenticatorChain (#10143) 2020-07-08 19:58:21 -07:00
Gian Merlino 11c0da8097
Add availability and consistency docs. (#10149)
* Add availability and consistency docs.

Describes transactional ingestion and atomic replacement. Also, this patch
deletes some bad advice from the javadocs for SegmentTransactionalInsertAction.

* Fix missing word.
2020-07-07 15:22:52 -07:00
Suneet Saldanha 15a0b4ffe2
Filter http requests by http method (#10085)
* Filter http requests by http method

Add a config that allows a user which http methods to allow against their
Druid server.

Druid will only accept http requests with the method: GET, PUT, POST, DELETE
and OPTIONS.
If a Druid admin wants to allow other methods, they can do so by using the
ServerConfig#allowedHttpMethods config.

If a Druid user would like to disallow OPTIONS, this can be done by changing
the AuthConfig#allowUnauthenticatedHttpOptions config

* Exclude OPTIONS from always supported HTTP methods

Add HEAD as an allowed method for web console e2e tests

* fix docs

* fix security IT

* Actually fix the web console e2e tests

* Ignore icode coverage for nitialization classes

* code review
2020-06-29 16:59:31 -07:00
Clint Wylie 0f51b3c190
fix dropwizard emitter jvm bufferpoolName metric (#10075)
* fix dropwizard emitter jvm bufferpoolName metric

* fixes
2020-06-25 12:20:25 -07:00
sthetland 978b494b46
Druid user permissions (#10047)
* Druid user permissions apply in the console

* Update index.md

* noting user warning in console page; some minor shuffling

* noting user warning in console page; some minor shuffling 1

* touchups

* link checking fixes

* Updated per suggestions
2020-06-23 17:39:48 -07:00
Gian Merlino 42590ae64b
Refresh query docs. (#9704)
* Refresh query docs.

Larger changes:

- New doc: querying/datasource.md describes the various kinds of
datasources you can use, and has examples for both SQL and native.
- New doc: querying/query-execution.md describes how native queries
are executed at a high level. It doesn't go into the details of specific
query engines or how queries run at a per-segment level. But I think it
would be good to add or link that content here in the future.
- Refreshed doc: querying/sql.md updated to refer to joins, reformatted
a bit, added a new "Query translation" section that explains how
queries are translated from SQL to native, and removed configuration
details (moved to configuration/index.md).
- Refreshed doc: querying/joins.md updated to refer to join datasources.

Smaller changes:

- Add helpful banners to the top of query documentation pages telling
people whether a given page describes SQL, native, or both.
- Add SQL metrics to operations/metrics.md.
- Add some color and cross-links in various places.
- Add native query component docs to the sidebar, and renamed them so
they look nicer.
- Remove Select query from the sidebar.
- Fix Broker SQL configs in configuration/index.md. Remove them from
querying/sql.md.
- Combined querying/searchquery.md and querying/searchqueryspec.md.

* Updates.

* Fix numbering.

* Fix glitches.

* Add new words to spellcheck file.

* Assorted changes.

* Further adjustments.

* Add missing punctuation.
2020-04-15 16:12:20 -07:00
Clint Wylie bf85ea19b2
roaring bitmaps by default (#9548)
* it is finally time

* fix it

* more docs

* fix doc
2020-03-23 18:15:57 -07:00
Roman Leventov b9186f8f9f Reconcile terminology and method naming to 'used/unused segments'; Rename MetadataSegmentManager to MetadataSegmentsManager (#7306)
* Reconcile terminology and method naming to 'used/unused segments'; Don't use terms 'enable/disable data source'; Rename MetadataSegmentManager to MetadataSegments; Make REST API methods which mark segments as used/unused to return server error instead of an empty response in case of error

* Fix brace

* Import order

* Rename withKillDataSourceWhitelist to withSpecificDataSourcesToKill

* Fix tests

* Fix tests by adding proper methods without interval parameters to IndexerMetadataStorageCoordinator instead of hacking with Intervals.ETERNITY

* More aligned names of DruidCoordinatorHelpers, rename several CoordinatorDynamicConfig parameters

* Rename ClientCompactTaskQuery to ClientCompactionTaskQuery for consistency with CompactionTask; ClientCompactQueryTuningConfig to ClientCompactionTaskQueryTuningConfig

* More variable and method renames

* Rename MetadataSegments to SegmentsMetadata

* Javadoc update

* Simplify SegmentsMetadata.getUnusedSegmentIntervals(), more javadocs

* Update Javadoc of VersionedIntervalTimeline.iterateAllObjects()

* Reorder imports

* Rename SegmentsMetadata.tryMark... methods to mark... and make them to return boolean and the numbers of segments changed and relay exceptions to callers

* Complete merge

* Add CollectionUtils.newTreeSet(); Refactor DruidCoordinatorRuntimeParams creation in tests

* Remove MetadataSegmentManager

* Rename millisLagSinceCoordinatorBecomesLeaderBeforeCanMarkAsUnusedOvershadowedSegments to leadingTimeMillisBeforeCanMarkAsUnusedOvershadowedSegments

* Fix tests, refactor DruidCluster creation in tests into DruidClusterBuilder

* Fix inspections

* Fix SQLMetadataSegmentManagerEmptyTest and rename it to SqlSegmentsMetadataEmptyTest

* Rename SegmentsAndMetadata to SegmentsAndCommitMetadata to reduce the similarity with SegmentsMetadata; Rename some methods

* Rename DruidCoordinatorHelper to CoordinatorDuty, refactor DruidCoordinator

* Unused import

* Optimize imports

* Rename IndexerSQLMetadataStorageCoordinator.getDataSourceMetadata() to retrieveDataSourceMetadata()

* Unused import

* Update terminology in datasource-view.tsx

* Fix label in datasource-view.spec.tsx.snap

* Fix lint errors in datasource-view.tsx

* Doc improvements

* Another attempt to please TSLint

* Another attempt to please TSLint

* Style fixes

* Fix IndexerSQLMetadataStorageCoordinator.createUsedSegmentsSqlQueryForIntervals() (wrong merge)

* Try to fix docs build issue

* Javadoc and spelling fixes

* Rename SegmentsMetadata to SegmentsMetadataManager, address other comments

* Address more comments
2020-01-27 11:24:29 -08:00
Gian Merlino d21054f7c5
Remove the deprecated interval-chunking stuff. (#9216)
* Remove the deprecated interval-chunking stuff.

See https://github.com/apache/druid/pull/6591, https://github.com/apache/druid/pull/4004#issuecomment-284171911 for details.

* Remove unused import.

* Remove chunkInterval too.
2020-01-19 17:14:23 -08:00
Jonathan Wei aa539177ec De-incubation cleanup in code, docs, packaging (#9108)
* De-incubation cleanup in code, docs, packaging

* remove unused docs script
2020-01-03 12:33:19 -05:00
Benjamin Hopp 13c33c1766 Update architecture.md (#9015) 2019-12-11 19:05:50 -08:00
Clint Wylie a48784a1fd dropwizard-emitter doc fixes (#8988) 2019-12-04 12:52:58 -08:00
Clint Wylie d67c3c7aed document SQL compatible null handling mode (#8894)
* document SQL compatible null handling mode

* adjustments

* fix docs

* review changes
2019-11-20 06:52:20 -08:00
Jad Naous d54d2e1627 Update segments.md (#8693)
Make bullet numbers clearer with parantheses, fix last reference to 2 being interpreted as a bullet point.
2019-10-17 11:55:23 -07:00
Jihoon Son 4046c86d62
Stateful auto compaction (#8573)
* Stateful auto compaction

* javaodc

* add removed test back

* fix test

* adding indexSpec to compactionState

* fix build

* add lastCompactionState

* address comments

* extract CompactionState

* fix doc

* fix build and test

* Add a task context to store compaction state; add javadoc

* fix it test
2019-10-15 22:57:42 -07:00
Abhishek Radhakrishnan d87840d894 Minor updates to documentation. (#8665) 2019-10-12 09:11:03 -07:00
Nishant Bangarwa 8537fbeca7 Implementing dropwizard emitter for druid (#7363)
* Implementing dropwizard emitter for druid

making metric manager and alert emitters as optional

* Refactor and make things work

more improvements

improve docs

refactrings

* Fix teamcity inspections

* review comments

* more review comments

* add limit to max number of gauges

* update pom version

* fix pom

* review comments

* review comment

* review comments

* fix broken doc link

review comments

review comments

* review comments

* fix checkstyle

* more spell check fixes

* fix travis failures
2019-10-01 14:59:30 -07:00
Nishant Bangarwa a75ddaad9e Add TrustedDomain Authenticator (#8248)
* Add TrustedDomain Authenticator

update javadoc

Add nullable annotations

Add cautionary note

fix travis failure

* add IP to spell checker
2019-09-25 11:25:03 -07:00
Chi Cao Minh 7dcbaca658 Spellcheck docs (#8548)
* Spellcheck docs

Fix spelling mistakes in docs and add CI job for running spellcheck on
docs.

* Add missing license header
2019-09-17 12:47:30 -07:00
Jonathan Wei 0145642d8b Move router/indexer config/API docs to main pages (#8510)
* Move router/indexer config/API docs to main pages

* Restore missing properties, fix typo

* Use sentence casing

* Fix broken link
2019-09-11 21:42:58 -07:00
Gian Merlino d007477742
Docusaurus build framework + ingestion doc refresh. (#8311)
* Docusaurus build framework + ingestion doc refresh.

* stick to npm instead of yarn

* fix typos

* restore some _bin

* Adjustments.

* detect and fix redirect anchors

* update anchor lint

* Web-console: remove specific column filters (#8343)

* add clear filter

* update tool kit

* remove usless check

* auto run

* add %

* Fix resource leak (#8337)

* Fix resource leak

* Patch comments

* Enable Spotbugs NP_NONNULL_RETURN_VIOLATION (#8234)

* Fixes from PR review.

* Fix more anchors.

* Preamble nix.

* Fix more anchors, headers

* clean up placeholder page

* add to website lint to travis config

* better broken link checking

* travis fix

* Fixed more broken links

* better redirects

* unfancy catch

* fix LGTM error

* link fixes

* fix md issues

* Addl fixes
2019-08-20 21:48:59 -07:00