Session timeline — all blocking & blocked sessions
One lane per session — click a sample to open its blocking tree
Each lane is one session, grouped into its wait chain (◆ = chain root, ↳ indent = depth in the chain).
Each cell is one ASH sample (≈10s). Filled cell = session was blocked that sample (color = "Color by");
outlined cell = session was only blocking others (holding the lock); filled with a dark border = waiting and blocking at once.
Click any cell to focus that sample and isolate that session's chain in the tree below;
click empty plot space to see all chains at that instant. Drag the slider to zoom long windows.
Drill-down — blocking tree at the selected sample
Blocking tree
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Root blockers anchor the left, waiters cascade right by depth; arrows point waiter → blocker. Node size = downstream impact, so the true root cause is the biggest dot. Blue = waiter, orange = blocks & waits, red = root blocker. Hover an edge for its wait event; click a node to list its own + downstream samples below.
Scroll to zoom, drag the background to pan — or use the − / + / Fit buttons above (handy when 50+ sessions fan in on one blocker). Drag the bottom edge of the panel to make it taller.
Sample detail
Click a cell in the timeline above, or a tree node, to populate this.