Unable to create client connection to Elasticsearch. Error:ConnectionError(error return without exception set) caused by: SystemError(error return without exception set)
This error can happen on non-secured connections as well. If it happens with a secured instance, it will usually be accompanied by one or more of the following messages
SNIMissingWarning: An HTTPS request has been made, but the SNI (Subject Name Indication) extension to TLS is not available on this platform. This may cause the server to present an incorrect TLS certificate, which can cause validation failures. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/advanced-usage.html#ssl-warnings
This happens on Python 2 versions older than 2.7.9. These older versions lack SNI support. This can cause servers to present a certificate that the client thinks is invalid. Follow the pyOpenSSL guide to resolve this warning.
InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/advanced-usage.html#ssl-warnings
This happens on Python 2 platforms that have an outdated ssl module. These older ssl modules can cause some insecure requests to succeed where they should fail and secure requests to fail where they should succeed. Follow the pyOpenSSL guide to resolve this warning.
InsecureRequestWarning: Unverified HTTPS request is being made. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.org/en/latest/security.html
This happens when an request is made to an HTTPS URL without certificate verification enabled. Follow the certificate verification guide to resolve this warning.
SSLError: [Errno 1] _ssl.c:510: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed