Getting error when doing count(*) from elassandra table

[jansee233]

Elasticsearch version:
"number" : "6.2.3",
"build_hash" : "e605ecd",
"build_date" : "2018-07-18T19:19:00.787857Z",
"build_snapshot" : false,
"lucene_version" : "7.2.1",
"minimum_wire_compatibility_version" : "5.6.0",
"minimum_index_compatibility_version" : "5.0.0"

Plugins installed: []

JVM version (java -version):
openjdk version "1.8.0_171"
OpenJDK Runtime Environment (build 1.8.0_171-8u171-b11-1~bpo8+1-b11)
OpenJDK 64-Bit Server VM (build 25.171-b11, mixed mode)

OS version (uname -a if on a Unix-like system):
Linux elassandra-0 4.15.0-1023-azure #24~16.04.1-Ubuntu SMP Wed Aug 29 12:54:36 UTC 2018 x86_64 GNU/Linux

Description of the problem including expected versus actual behavior:

Getting error when doing count() from elassandra table when it has more data" ReadTimeout: Error from server: code=1200 [Coordinator node timed out waiting for replica nodes' responses] message="Operation timed o ut - received only 0 responses." info={'received_responses': 0, 'required_responses': 1, 'consistency': 'ONE'}" to Getting error when doing count() from elassandra
Steps to reproduce:

Please include a minimal but complete recreation of the problem, including
(e.g.) index creation, mappings, settings, query etc. The easier you make for
us to reproduce it, the more likely that somebody will take the time to look at it.

Provide logs (if relevant):

[DBarthe]

If your table is huge, count(*) can easily timeout.

You can increase the cqlsh timeout with :

 --connect-timeout=CONNECT_TIMEOUT
                       Specify the connection timeout in seconds (default: 5
                       seconds).
 --request-timeout=REQUEST_TIMEOUT
                       Specify the default request timeout in seconds
                       (default: 10 seconds).

Unlike a RDBMS, counting the number of records is an heavy operation in Cassandra (due to its distributed nature). Checkout this article if you want more understanding.

You may want to use nodetool tablestats to get some rough approximations about your tables.

[jansee233]

spark job is writing data into elassandra tables. where to add --connect-timeout=CONNECT_TIMEOUT parameter as it should affect to all elassandra pods

[DBarthe]

Under spark, it should be spark.cassandra.read.timeout_ms, see
https://github.com/datastax/spark-cassandra-connector/blob/master/doc/reference.md (never tried myself)