Ignore clusterstate.json. Fixes #224.

[rokclimb15]

Remove clusterstate.json and listener since the node exists but Solr no longer updates it. This resulted in the collections property being overwritten with an empty state. Tested on Solr 7.7.2. Below is log output during a connection/index/search routine. Without clusterstate being watched the ZooKeeper class correctly connects to live_nodes, polls collections, and polls the collection state to get shards.

Updated live nodes: ['172.31.80.126:8983_solr', '172.31.85.226:8983_solr', '172.31.84.9:8983_solr', '172.31.87.69:8983_solr']
Updated aliases: None
Updated collection: ['staging']
Updated collections: {'staging': {'pullReplicas': '0', 'replicationFactor': '2', 'router': {'name': 'compositeId'}, 'maxShardsPerNode': '1', 'autoAddReplicas': 'false', 'nrtReplicas': '2', 'tlogReplicas': '0', 'shards': {'shard1': {'range': '80000000-7fffffff', 'state': 'active', 'replicas': {'core_node3': {'core': 'staging_shard1_replica_n1', 'base_url': 'http://172.31.85.226:8983/solr', 'node_name': '172.31.85.226:8983_solr', 'state': 'recovery_failed', 'type': 'NRT', 'force_set_state': 'false'}, 'core_node4': {'core': 'staging_shard1_replica_n2', 'base_url': 'http://172.31.80.126:8983/solr', 'node_name': '172.31.80.126:8983_solr', 'state': 'active', 'type': 'NRT', 'force_set_state': 'false', 'leader': 'true'}}}}}}

I attempted to run the test suite, but it looks like the Solr package referenced is 404 in the test script. Additionally, Solr 4 is unsupported at this point I think.

[acdha]

Is there any upstream documentation about this being deprecated? We should probably have some sort of documentation / release notes link since I'm assuming there's at least some older version of Solr someone is running where this still works.

[rokclimb15]

I wasn't able to find any official documentation, likely because this is the internal API of Solr with ZooKeeper and is subject to change. The "official" way to do this would be to call the Solr HTTP API.

I think it would make sense to do this in the context of a BC release and update the test suite to run Solr >= 7 (supported). I started to do that, but ran into a few snags with config files.

[codecov]

Codecov Report

Merging #315 into master will decrease coverage by 6.60%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #315      +/-   ##
==========================================
- Coverage   94.35%   87.74%   -6.61%     
==========================================
  Files           7        7              
  Lines        1328     1322       -6     
==========================================
- Hits         1253     1160      -93     
- Misses         75      162      +87     

Impacted Files	Coverage Δ
pysolr.py	79.88% <ø> (-9.65%)	⬇️
tests/test_cloud.py	46.15% <0.00%> (-53.85%)	⬇️

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[cclauss]

Please rebase to run the tests.

[cclauss]

@rokclimb15 Please rebase or close.

[rokclimb15]

Closing in favor of #426