anchor.diff:  jacknich       : monitoring,unknown_role* <1>
   ------------------------------------------
   <1> `unknown_role` was not found in `roles.yml`
  ---
  -
  -ERROR: extra arguments [...] were provided::
  -+
  ---
  -This error occurs when the `users` tool is parsing the input and finds unexepected arguments. This can happen when there
  -are special characters used in some of the arguments. For example, on Windows systems the `,` character is considered
  -a parameter separator; in other words `-r role1,role2` is translated to `-r role1 role2` and the `users` tool only recognizes
  -`role1` as an expected parameter. The solution here is to quote the parameter: `-r "role1,role2"`.
  ---
  -
  -[[trouble-shoot-active-directory]]
  -[float]
  -=== Active Directory
  -
  -Certain users are being frequently locked out of Active Directory::
  -+
  ---
  -Check your realm configuration; realms are checked serially, one after another. If your Active Directory realm is being checked before other realms and there are usernames
  -that appear in both Active Directory and another realm, a valid login for one realm may be causing failed login attempts in another realm.
  -
  -For example, if `UserA` exists in both Active Directory and a file realm, and the Active Directory realm is checked first and
  -file is checked second, an attempt to authenticate as `UserA` in the file realm would first attempt to authenticate
  -against Active Directory and fail, before successfully authenticating against the `file` realm. Because authentication is
  -verified on each request, the Active Directory realm would be checked - and fail - on each request for `UserA` in the `file`
  -realm. In this case, while the authentication request completed successfully, the account on Active Directory would have received
  -several failed login attempts, and that account may become temporarily locked out. Plan the order of your realms accordingly.
  -
  -Also note that it is not typically necessary to define multiple Active Directory realms to handle domain controller failures. When using Microsoft DNS, the DNS entry for the domain should always point to an available domain controller.
  ---
  -
  -[float]
  -=== LDAP
  -
  -I can authenticate to LDAP, but I still get an authorization exception::
  -+
  ---
  -A number of configuration options can cause this error.
  -
  +
  +For more information about this command, see
  +{ref}/users-command.html[Users Command].
  +--
  +
  +. If you are authenticating to LDAP, a number of configuration options can cause
  +this error.
  ++
  +--
   |======================
   |_group identification_ |
   
  
positive.code: logger.authc.level = DEBUG
  ----------------
  
  A successful authentication should produce debug statements that list groups and role mappings.
  --
  
  
  [float]
  === Encryption & Certificates
  
  `curl` on the Mac returns a certificate verification error even when the `--cacert` option is used::
  +
  --
  Apple's integration of `curl` with their keychain technology disables the `--cacert` option.
  See http://curl.haxx.se/mail/archive-2013-10/0036.html for more information.
  
  You can use another tool, such as `wget`, to test certificates. Alternately, you can add the certificate for the
  signing certificate authority MacOS system keychain, using a procedure similar to the one detailed at the
  http://support.apple.com/kb/PH14003[Apple knowledge base]. Be sure to add the signing CA's certificate and not the server's certificate.
  --
  
  [float]
  ==== SSLHandshakeException causing connections to fail
  
  A `SSLHandshakeException` will cause a connection to a node to fail and indicates that there is a configuration issue. Some of the
  common exceptions are shown below with tips on how to resolve these issues.
  
  `java.security.cert.CertificateException: No name matching node01.example.com found`::
  +
  --
  Indicates that a client connection was made to `node01.example.com` but the certificate returned did not contain the name `node01.example.com`.
  In most cases, the issue can be resolved by ensuring the name is specified during certificate creation. For more information, see <<ssl-tls>>.
  Another scenario is when the environment does not wish to use DNS names in certificates at all. In this scenario, all settings
  in `elasticsearch.yml` should only use IP addresses including the `network.publish_host` setting.
  --
  
  `java.security.cert.CertificateException: No subject alternative names present`::
  +
  --
  Indicates that a client connection was made to an IP address but the returned certificate did not contain any `SubjectAlternativeName` entries.
  IP addresses are only used for hostname verification if they are specified as a `SubjectAlternativeName` during certificate creation. If the intent was to use IP addresses for hostname verification, then the certificate
  will need to be regenerated with the appropriate IP address. See <<ssl-tls>>.
  --
  
  `javax.net.ssl.SSLHandshakeException: null cert chain` and `javax.net.ssl.SSLException: Received fatal alert: bad_certificate`::
  +
  --
  The `SSLHandshakeException` above indicates that a self-signed certificate was returned by the client that is not trusted
  as it cannot be found in the `truststore` or `keystore`. The `SSLException` above is seen on the client side of the connection.
  --
  
  `sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target` and `javax.net.ssl.SSLException: Received fatal alert: certificate_unknown`::
  +
  --
  The `SunCertPathBuilderException` above indicates that a certificate was returned during the handshake that is not trusted.
  This message is seen on the client side of the connection. The `SSLException` above is seen on the server side of the
  connection. The CA certificate that signed the returned certificate was not found in the `keystore` or `truststore` and
  needs to be added to trust this certificate.
  --
  
  [float]
  ==== Other SSL/TLS related exceptions
  
  The are other exceptions related to SSL that may be seen in the logs. Below you will find some common exceptions and their
  meaning.
  
  WARN: received plaintext http traffic on a https channel, closing connection::
  +
  --
  Indicates that there was an incoming plaintext http request. This typically occurs when an external applications attempts
  to make an unencrypted call to the REST interface. Please ensure that all applications are using `https` when calling the
  REST interface with SSL enabled.
  --
  
  `org.elasticsearch.common.netty.handler.ssl.NotSslRecordException: not an SSL/TLS record:`::
  +
  --
  Indicates that there was incoming plaintext traffic on an SSL connection. This typically occurs when a node is not
  configured to use encrypted communication and tries to connect to nodes that are using encrypted communication. Please
  verify that all nodes are using the same setting for `xpack.security.transport.ssl.enabled`.
  --
  
  `java.io.StreamCorruptedException: invalid internal transport message format, got`::
  +
  --
  Indicates an issue with data received on the transport interface in an unknown format. This can happen when a node with
  encrypted communication enabled connects to a node that has encrypted communication disabled. Please verify that all
  nodes are using the same setting for `xpack.security.transport.ssl.enabled`.
  --
  
  `java.lang.IllegalArgumentException: empty text`::
  +
  --
  The exception is typically seen when a `https` request is made to a node that is not using `https`. If `https` is desired,
  please ensure the following setting is in `elasticsearch.yml`:
  
  [source,yaml]
  ----------------
  xpack.security.http.ssl.enabled: true
  ----------------
  --
  
  ERROR: unsupported ciphers [...] were requested but cannot be used in this JVM::
  +
  --
  This error occurs when a SSL/TLS cipher suite is specified that cannot supported by the JVM that Elasticsearch is running
  in. Security will try to use the specified cipher suites that are supported by this JVM. This error can occur when using
  the Security defaults as some distributions of OpenJDK do not enable the PKCS11 provider by default. In this case, we
  recommend consulting your JVM documentation for details on how to enable the PKCS11 provider.
  
  Another common source of this error is requesting cipher suites that use encrypting with a key length greater than 128 bits
  when running on an Oracle JDK. In this case, you will need to install the <<ciphers, JCE Unlimited Strength Jurisdiction Policy Files>>.
  --
  
  [float]
  ==== Internal Server Error in Kibana
  
  If the Security plugin is enabled in Elasticsearch but disabled in Kibana, you must
  still set `elasticsearch.username` and `elasticsearch.password` in `kibana.yml`.
  Otherwise, Kibana cannot connect to Elasticsearch. In 5.1.1, this results in an
  `UnhandledPromiseRejectionWarning` and Kibana displays an Internal Server Error.
  
negative.code: 
  |_role definition_|
  
  The role definition might be missing or invalid.
  
  |======================
  
  To help track down these possibilities, add the following lines to the end of
  the `log4j2.properties` configuration file in the `CONFIG_DIR`:
  
  [source,properties]
  ----------------
  