Snapshot and Restore 6.8.8 - Null Pointer Exception after Upgrade from 6.2.4 to 6.8.8

[Neha_Wagholikar]

Hi,

I have upgraded my ELK from 6.2.4 to 6.8.8.
Used Azure plugin for Snapshot
Before Upgrade, my backup was working fine on both Public and Azure Stack.
After Upgrade ,On public I am able to take backup but on Azure Stack I am not able to take backup , its showing below error :

{
"error" : {
"root_cause" : [
{
"type" : "storage_exception",
"reason" : "storage_exception: The value for one of the HTTP headers is not in the correct format."
}
],
"type" : "no_such_element_exception",
"reason" : "no_such_element_exception: An error occurred while enumerating the result, check the original exception for details.",
"caused_by" : {
"type" : "storage_exception",
"reason" : "storage_exception: The value for one of the HTTP headers is not in the correct format.",
"caused_by" : {
"type" : "null_pointer_exception",
"reason" : null
}
}
},
"status" : 500
}

curl -XPUT "http://:9200/_snapshot/FullBackup-04062020" -H 'Content-Type: application/json' -d'

{
    "type": "azure",
    "settings": {
        "compress" : true,
        "container": "elkacf",
        "base_path": "FullBackup-04062020"
    }
}'

{"error":{"root_cause":[{"type":"repository_verification_exception","reason":"[FullBackup-04062020] path [FullBackup-04062020] is not accessible on master node"}],"type":"repository_verification_exception","reason":"[FullBackup-04062020] path [FullBackup-04062020] is not accessible on master node","caused_by":{"type":"i_o_exception","reason":"Can not write blob master.dat","caused_by":{"type":"storage_exception","reason":"storage_exception: The value for one of the HTTP headers is not in the correct format.","caused_by":{"type":"null_pointer_exception","reason":null}}}},"status":500}

"caused_by":{"type":"storage_exception","reason":"storage_exception: The value for one of the HTTP headers is not in the correct format.",

What are the HTTP headers used in Elasticsearch snapshot?

Added this setting :
1] azure.client.default.endpoint_suffix:
2] bin/elasticsearch-keystore add azure.client.default.account
3] bin/elasticsearch-keystore add azure.client.default.key