When you have many catalog items published to or subscribed from other organizations, to avoid overloading the system during catalog synchronizations, you can configure catalog synchronization throttling. You can use the manage-config subcommand of the cell management tool to configure catalog synchronization throttling by limiting the number of library items that can be synced at the same time.

When a subscribed catalog initiates a catalog synchronization, the published catalog first downloads the library items from the vCenter Server repository to the vCloud Director transfer service storage, then creates download links for the subscribed catalog. You can limit the number of library items that all published catalogs can download at the same time. You can limit the number of library items that all subscribed catalogs can sync at the same time. You can limit the number of library items that a single subscribed catalog can sync at the same time.

You can use the manage-config subcommand of the cell management tool to update the configuration settings for catalog throttling. For information about using the manage-config subcommand, see Updating Application Configuration Settings.

Table 1. Configuration Settings for Catalog Throttling
Configuration Setting Default Value Description
vcloud.tasks.VDC_ENABLE_DOWNLOAD.queue.limit 30 The limit of library items that all published catalogs in the vCloud Director instance can download from vCenter Server to vCloud Director at the same time.

If the total number of published library items for downloading across the vCloud Director instance is greater than this limit, the library items are divided into portions by this limit and downloaded in a sequence.

vcloud.tasks.LIBRARY_ITEM_SYNC.queue.limit 30 The limit of library items that all subscribed catalogs in a vCloud Director instance can sync at the same time.

If the total number of subscribed library items for syncing across the vCloud Director instance is greater than this limit, the items are divided into portions by this limit and synced in a sequence.

contentLibrary.item.sync.batch.size 10 The limit of library items that a single subscribed catalog can sync at the same time.

If a subscribed catalog tries to sync a number of library items that is greater than this limit, the items are divided into portions by this limit and synced in a sequence.

Configuring Synchronization Throttling for Subscribed Catalogs

The following command sets a limit of five for the library items that a single subscribed catalog can sync at the same time.

[root@cell1 /opt/vmware/vcloud-director/bin]#./cell-management-tool manage-config -n contentLibrary.item.sync.batch.size -v 5

If a subscribed catalog contains 13 library items, syncing the catalog is performed in three sequential portions. The first portion contains five items, the second portion contains the next five items, the last portion contains the remaining three items.