Category Archives: Cassandra

從 Cassandra 到 ScyllaDB 的轉移方式好像跟以前不太一樣了...

在「New Docs: Four Phases to Migrate from Apache Cassandra to Scylla」這邊看到 ScyllaDB 官方提供 Cassandra 轉移到 ScyllaDB 的說明,跟以前好像差蠻多的... 以前 ScyllaDB 可以直接加入到 Cassandra 的 cluster (一時間沒找到資料,但在「can not add node with cassandra ami · Issue #107 · scylladb/scylla-cluster-tests」可以看到當時的痕跡),現在給的方法是在資料庫不相容時的轉移方式 (像是從 MySQL 轉換到 PostgreSQL 這種),是暗示已經沒辦法這樣做了嗎? … Continue reading

Posted in Cassandra, Computer, Database, Murmuring, Network, Software|Tagged , , , , , , , |Leave a comment

Reddit 在處理 Page View 的方式

Reddit 說明了他們如何處理 pageview:「View Counting at Reddit」。 以 Reddit 的規模有提到兩個重點,第一個在善用 Redis 的 HyperLogLog 這個資料結構,當量大的時候其實可以允許有微小的誤差: The amount of memory varies per implementation, but in the case of this implementation, we could count over 1 million IDs using just 12 kilobytes of space, … Continue reading

Posted in Cassandra, Computer, Database, Murmuring, Network, Programming, Service, Software|Tagged , , , , , , , , , , , , , , , , , , , |Leave a comment

ScyllaDB 1.7 支援 Counters 了

在「Scylla release: version 1.7」這邊看到 ScyllaDB 支援 Counters 的消息了 (雖然剛出來,掛著 Experimental 的消息): Scylla now supports Counters as a native type. A counter column is a column whose value is a 64-bit signed integer and on which two operations are supported: incrementing … Continue reading

Posted in Cassandra, Computer, Database, Network, Software|Tagged , , , , , , , , |Leave a comment