# Slow search and tiny segments memory\_in\_bytes after upgrade \>= es7.9
**URL:** https://discuss.elastic.co/t/slow-search-and-tiny-segments-memory-in-bytes-after-upgrade-es7-9/269174
**Category:** Elasticsearch
**Created:** [April 4, 2021, 9:27am UTC](https://discuss.elastic.co/t/slow-search-and-tiny-segments-memory-in-bytes-after-upgrade-es7-9/269174 "2021-04-04T09:27:52Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@MihaylovNikitos](https://discuss.elastic.co/u/MihaylovNikitos)
#### Post date: [April 4, 2021, 9:27am UTC](https://discuss.elastic.co/t/slow-search-and-tiny-segments-memory-in-bytes-after-upgrade-es7-9/269174/1 "2021-04-04T09:27:52Z")
Hi
After upgrading from ES 7.8.x to ES \>=7.9, I noticed that segments `*_memory_in_bytes` became very small and search is very slow
It is seen by stats:
**ES 7.8.1**
/\_nodes/stats
```
segments:
{
count: 7,
memory_in_bytes: 2964866,
terms_memory_in_bytes: 2952362,
stored_fields_memory_in_bytes: 7160,
term_vectors_memory_in_bytes: 0,
norms_memory_in_bytes: 0,
points_memory_in_bytes: 4812,
doc_values_memory_in_bytes: 532,
index_writer_memory_in_bytes: 0,
version_map_memory_in_bytes: 0,
fixed_bit_set_memory_in_bytes: 0,
max_unsafe_auto_id_timestamp: -1,
file_sizes: { }
},
```
/\_cat/segment
```
index shard prirep ip segment generation docs.count docs.deleted size size.memory committed searchable version compound
test-index 0 p 172.26.0.3 _0 0 181104 0 313.6mb 564872 true true 8.5.1 true
```
After merge:
```auto
test-index 0 p 172.26.0.3 _7 7 1000000 0 1.6gb 1834676 true false 8.5.1 false
```
Search {"query": {"term": {"id": xxx}} is performed at ~1000doc/s
**ES \>= 7.9**
\_nodes/stats
```
segments:
{
count: 7,
memory_in_bytes: 28444,
terms_memory_in_bytes: 20832,
stored_fields_memory_in_bytes: 7080,
term_vectors_memory_in_bytes: 0,
norms_memory_in_bytes: 0,
points_memory_in_bytes: 0,
doc_values_memory_in_bytes: 532,
index_writer_memory_in_bytes: 0,
version_map_memory_in_bytes: 0,
fixed_bit_set_memory_in_bytes: 0,
max_unsafe_auto_id_timestamp: -1,
file_sizes: { }
},
```
\_cat/segment
```
index shard prirep ip segment generation docs.count docs.deleted size size.memory committed searchable version compound
test-index 0 p 172.28.0.7 _0 0 185307 0 320.5mb 4228 false false 8.6.0 true
```
After merge:
```auto
test-index 0 p 172.28.0.7 _7 7 1000000 0 1.6gb 7396 true true 8.6.0 false
```
Search {"query": {"term": {"id": xxx}} is performed at ~500doc/s
* * *
Configs
I run ES in docker, official images from [docker.elastic.co](http://docker.elastic.co)
Index:
```
{
"settings": {
"store.type": "niofs",
"refresh_interval": "600s",
"translog.flush_threshold_size": "512mb",
"number_of_shards": 1,
"number_of_replicas": 0,
},
'mappings': {
"dynamic": False,
'properties': {
'id': {'type': 'keyword'},
field0: {'type': 'keyword'},
field1: {'type': 'keyword'},
field2: {'type': 'keyword'},
field3: {'type': 'keyword'},
field4: {'type': 'keyword'},
field5: {'type': 'keyword'},
field6: {'type': 'keyword'},
field7: {'type': 'keyword'},
field8: {'type': 'keyword'},
field9: {'type': 'keyword'},
field10: {'type': 'keyword'},
}}
}
```
Data:
_id, fieldX_ - is just a unique short string, e.g. `str (uuid.uuid4 ()) * 2` (but it doesn't matter, other values are possible)
* * *
I tried to change config index/cluster, but did not notice a positive result.
What could be the problem? Is this a bug or a feature?
---
### Author:  [@MihaylovNikitos](https://discuss.elastic.co/u/MihaylovNikitos)
#### Post date: [April 6, 2021, 3:57am UTC](https://discuss.elastic.co/t/slow-search-and-tiny-segments-memory-in-bytes-after-upgrade-es7-9/269174/2 "2021-04-06T03:57:11Z")
While testing, I realized that it happened after [https://issues.apache.org/jira/browse/LUCENE-9257](https://issues.apache.org/jira/browse/LUCENE-9257)(commit e7a61ea)
Asked the developers on IRC # lucene
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [May 4, 2021, 3:58am UTC](https://discuss.elastic.co/t/slow-search-and-tiny-segments-memory-in-bytes-after-upgrade-es7-9/269174/3 "2021-05-04T03:58:04Z")
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