Interpreting the output of elasticsearch GET query - elasticsearch

Question

The output of the curl -X GET "localhost:9200/_cat/shards?v" is as follows:
index
shard
prirep
state
docs
store
ip
node
test_index
1
p
STARTED
0
283b
127.0.0.1
Deepaks-MacBook-Pro-2.local
test_index
1
r
UNASSIGNED
0
test_index
1
r
UNASSIGNED
0
test_index
0
p
STARTED
1
12.5kb
127.0.0.1
Deepaks-MacBook-Pro-2.local
test_index
0
r
UNASSIGNED
0
test_index
0
r
UNASSIGNED
0
And the output of the query curl -X GET "localhost:9200/test_index/_search?size=1000" | json_pp is as follows:
{
"_shards" : {
"failed" : 0,
"skipped" : 0,
"successful" : 2,
"total" : 2
},
"hits" : {
"hits" : [
{
"_id" : "101",
"_index" : "test_index",
"_score" : 1,
"_source" : {
"in_stock" : -4,
"name" : "pizza maker",
"prize" : 10
},
"_type" : "_doc"
}
],
"max_score" : 1,
"total" : {
"relation" : "eq",
"value" : 1
}
},
"timed_out" : false,
"took" : 2
}
MY QUESTION: As you can see, only text_index 0 primary shard has the data (from the output of first query), why successful key inside the _shards key has the value of 2?
Also, there is only 1 document, then why the value of total key inside _shards key is 2?

Answer 1

test_index has two primary shards and four unassigned replica shards (probably because you have a single node). Since a primary shard is a partition of your index, a document can only be stored in a single primary shard, in your case primary shard 0.
total: 2 means that the search was run over the two primary shards of your index (i.e. 100% of the data) and successful: 2 means that all primary shards responded. So you know you can trust the response to have searched over all your test_index data.
There's nothing wrong here.