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Pritesh Maker updated DRILL-5771: --------------------------------- Reviewer: Timothy Farkas > Fix serDe errors for format plugins > ----------------------------------- > > Key: DRILL-5771 > URL: https://issues.apache.org/jira/browse/DRILL-5771 > Project: Apache Drill > Issue Type: Bug > Affects Versions: 1.11.0 > Reporter: Arina Ielchiieva > Assignee: Arina Ielchiieva > Priority: Minor > Fix For: 1.12.0 > > > Create unit tests to check that all storage format plugins can be > successfully serialized / deserialized. > Usually this happens when query has several major fragments. > One way to check serde is to generate physical plan (generated as json) and > then submit it back to Drill. > One example of found errors is described in the first comment. Another > example is described in DRILL-5166. > *Serde issues:* > 1. Could not obtain format plugin during deserialization > Format plugin is created based on format plugin configuration or its name. > On Drill start up we load information about available plugins (its reloaded > each time storage plugin is updated, can be done only by admin). > When query is parsed, we try to get plugin from the available ones, it we can > not find one we try to [create > one|https://github.com/apache/drill/blob/3e8b01d5b0d3013e3811913f0fd6028b22c1ac3f/exec/java-exec/src/main/java/org/apache/drill/exec/store/dfs/FileSystemPlugin.java#L136-L144] > but on other query execution stages we always assume that [plugin exists > based on > configuration|https://github.com/apache/drill/blob/3e8b01d5b0d3013e3811913f0fd6028b22c1ac3f/exec/java-exec/src/main/java/org/apache/drill/exec/store/dfs/FileSystemPlugin.java#L156-L162]. > For example, during query parsing we had to create format plugin on one node > based on format configuration. > Then we have sent major fragment to the different node where we used this > format configuration we could not get format plugin based on it and > deserialization has failed. > To fix this problem we need to create format plugin during query > deserialization if it's absent. > > 2. Absent hash code and equals. > Format plugins are stored in hash map where key is format plugin config. > Since some format plugin configs did not have overridden hash code and > equals, we could not find format plugin based on its configuration. > 3. Named format plugin usage > Named format plugins configs allow to get format plugin by its name for > configuration shared among all drillbits. > They are used as alias for pre-configured format plugiins. User with admin > priliges can modify them at runtime. > Named format plugins configs are used instead of sending all non-default > parameters of format plugin config, in this case only name is sent. > Their usage in distributed system may cause raise conditions. > For example, > 1. Query is submitted. > 2. Parquet format plugin is created with the following configuration > (autoCorrectCorruptDates=>true). > 3. Seralized named format plugin config with name as parquet. > 4. Major fragment is sent to the different node. > 5. Admin has changed parquet configuration for the alias 'parquet' on all > nodes to autoCorrectCorruptDates=>false. > 6. Named format is deserialized on the different node into parquet format > plugin with configuration (autoCorrectCorruptDates=>false). -- This message was sent by Atlassian JIRA (v6.4.14#64029)