for example:
start a node by ignite.sh.
then:
CREATE TABLE City (
ID INT,
Name VARCHAR,
CountryCode CHAR(3),
District VARCHAR,
Population INT,
PRIMARY KEY (ID, CountryCode)
) WITH "template=partitioned, backups=1, affinityKey=CountryCode,
CACHE_NAME=City, KEY_TYPE=demo.model.CityKey, VALUE_TYPE=demo.model.City";
INSERT INTO City(ID, Name, CountryCode, District, Population) VALUES
(1,'Kabul','AFG','Kabol',1780000);
INSERT INTO City(ID, Name, CountryCode, District, Population) VALUES
(2,'Qandahar','AFG','Qandahar',237500);
INSERT INTO City(ID, Name, CountryCode, District, Population) VALUES
(3,'Herat','AFG','Herat',186800);
INSERT INTO City(ID, Name, CountryCode, District, Population) VALUES
(4,'Mazar-e-Sharif','AFG','Balkh',127800);
INSERT INTO City(ID, Name, CountryCode, District, Population) VALUES
(5,'Amsterdam','NLD','Noord-Holland',731200);
INSERT INTO City(ID, Name, CountryCode, District, Population) VALUES
(6,'Rotterdam','NLD','Zuid-Holland',593321);
INSERT INTO City(ID, Name, CountryCode, District, Population) VALUES
(7,'Haag','NLD','Zuid-Holland',440900);
INSERT INTO City(ID, Name, CountryCode, District, Population) VALUES
(8,'Utrecht','NLD','Utrecht',234323);
INSERT INTO City(ID, Name, CountryCode, District, Population) VALUES
(9,'Eindhoven','NLD','Noord-Brabant',201843);
INSERT INTO City(ID, Name, CountryCode, District, Population) VALUES
(10,'Tilburg','NLD','Noord-Brabant',193238);
INSERT INTO City(ID, Name, CountryCode, District, Population) VALUES
(11,'Groningen','NLD','Groningen',172701);
SELECT * FROM sys.metrics WHERE name LIKE 'io.dataregion.default%';
io.dataregion.default.OffHeapSize 104857600
io.dataregion.default.PhysicalMemoryPages 2066
io.dataregion.default.EmptyDataPages 0
io.dataregion.default.UsedCheckpointBufferSize 0
io.dataregion.default.TotalThrottlingTime 0
io.dataregion.default.PagesReplaced 0
io.dataregion.default.EvictionRate 0
io.dataregion.default.InitialSize 104857600
io.dataregion.default.DirtyPages 0
io.dataregion.default.MaxSize 8589934592
io.dataregion.default.PagesWritten 0
io.dataregion.default.PagesReplaceRate 0
io.dataregion.default.PagesRead 0
io.dataregion.default.PagesFillFactor 0.9997031688690186
io.dataregion.default.TotalAllocatedPages 2066
io.dataregion.default.PhysicalMemorySize 8511920
io.dataregion.default.PagesReplaceAge 0
io.dataregion.default.AllocationRate 2066
io.dataregion.default.OffheapUsedSize 8511920
io.dataregion.default.LargeEntriesPagesCount 0
io.dataregion.default.TotalAllocatedSize 8511920
io.dataregion.default.CheckpointBufferSize 0
TotalUsedSize - (TotalAllocatedSize - PagesFillFactor * TotalAllocatedSize)
= 8511920 - (8511920 - 0.9997031688690186 * 8511920) = 8509392
delete from city;
SELECT * FROM sys.metrics WHERE name LIKE 'io.dataregion.default%';
io.dataregion.default.OffHeapSize 104857600
io.dataregion.default.PhysicalMemoryPages 2075
io.dataregion.default.EmptyDataPages 0
io.dataregion.default.UsedCheckpointBufferSize 0
io.dataregion.default.TotalThrottlingTime 0
io.dataregion.default.PagesReplaced 0
io.dataregion.default.EvictionRate 0
io.dataregion.default.InitialSize 104857600
io.dataregion.default.DirtyPages 0
io.dataregion.default.MaxSize 8589934592
io.dataregion.default.PagesWritten 0
io.dataregion.default.PagesReplaceRate 0
io.dataregion.default.PagesRead 0
io.dataregion.default.PagesFillFactor 1.0
io.dataregion.default.TotalAllocatedPages 2075
io.dataregion.default.PhysicalMemorySize 8549000
io.dataregion.default.PagesReplaceAge 0
io.dataregion.default.AllocationRate 9
io.dataregion.default.OffheapUsedSize 8549000
io.dataregion.default.LargeEntriesPagesCount 0
io.dataregion.default.TotalAllocatedSize 8549000
io.dataregion.default.CheckpointBufferSize 0
TotalUsedSize - (TotalAllocatedSize - PagesFillFactor * TotalAllocatedSize)
=8549000 - (8549000 - 1.0 * 8549000) = 8549000
Instead, the value becomes larger?
在 2022/9/19 15:13, Alexander Polovtcev 写道:
Sorry, I messed up the metric names a little bit, we should use the
size metrics, not the page metrics. So the correct formula would be:
`TotalUsedSize - (TotalAllocatedSize - PagesFillFactor *
TotalAllocatedSize)`
On Sun, Sep 18, 2022 at 4:29 PM 38797715 <[email protected]> wrote:
I've checked TotalUsedPages in ignite.dataRegionMetrics(), it is
found that the logic of this metric is consistent with
OffheapUsedSize, that is, the value will not be updated after data
deletion.
在 2022/9/18 19:42, Alexander Polovtcev 写道:
Hello, you can check out "TotalUsedPages" and "TotalUsedSize"
metrics that can be found in the Data Region metrics. However,
please keep in mind that this does not take page fragmentation
into account.
On Sat, Sep 17, 2022 at 2:35 PM 38797715 <[email protected]> wrote:
Hi team,
We found that if the delete operation is executed, the memory
space corresponding to the data will not be released, and
this space will be reused later.
Therefore, metrics such as OffheapUsedSize will become
inaccurate.
So, how to calculate the exact amount of memory occupied by
data in a cache or a dataregion?
--
With regards,
Aleksandr Polovtcev
--
With regards,
Aleksandr Polovtcev
